U.S. PATENT AND TRADEMARK OFFICE
Information Products Division |
U.S. Patent Classification System - Classification Definitions
as of June 30, 2000
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Class 333
WAVE TRANSMISSION LINES AND NETWORKS
Class Definition:
A. GENERAL STATEMENT OF THE CLASS SUBJECT MATTER
1. This class includes electric wave transmission systems
wherein electromagnetic wave energy is guided or constrained
by a wave transmission device of the long line type other
than loaded lines.
2. Included are passive wave transmission networks simulating
the characteristics of a long line wave transmission systems
or wave guides, such as artificial lines, delay networks,
resonators, impedance matching networks, equalizers, wave
filters and transmission line terminations.
3. Also included are passive coupling networks and
terminating networks having either lumped or distributed
electrical circuit parameters and having impedance
characteristics peculiarly adapted for use with the wave
transmission systems of paragraph 1, above, or which are
designed to be frequency responsive, or which are designed to
be effective over or within a range of frequencies, for
example, impedance matching networks, hybrid networks,
coupling networks, wave shaping networks, phase shifting
networks, wave filters, equalizers and attenuators.
4. Smoothing type wave filters having shunt capacitance, or
series inductance, or both, usually designed to pass direct
current and to reduce the effect of any undesired alternating
or pulsating current superimposed on the direct current, or
to pass direct current and low frequency alternating current
or pulsating current and to reduce the effect of an undesired
higher frequency alternating or pulsating current.
5. Networks including a wave transmission device and means
for decreasing the amplitude range of the signal applied to
the transmission device as the signal increases in amplitude
and means for increasing or restoring the amplitude range of
the signal after the transmission over the transmission
device (i.e., companders).
6. Passive networks for producing an output wave which is the
time derivative or time integral of the input wave (i.e.,
differentiating or integrating systems).
7. Systems including active elements for producing across at
least two of the system terminals a negative resistance,
and/or an inductance, or capacitance which may be positive or
negative.
8. Wave traps using long line elements.
9. Transmission systems including only one or more of the
systems or networks defined in paragraphs 1 - 8, above, and
such systems in combination with current or voltage magnitude
control means of the passive type. Systems including two or
more of the networks or systems defined in paragraphs 1 - 8,
above, are classified as set forth in the Class Definition,
subsection C, below.
10. Components and elements not constituting a complete
system or network limited by claimed structure to use in the
systems or network of paragraph 1, above, and not otherwise
classified, and also long line elements.
B. ACTIVE NETWORK
The systems classified in this class ordinarily contain no
active elements, the only exceptions being the amplitude
compression and expansion systems (companders) and negative
resistance and/or reactance networks of the active element
type found in this class. See Subclass References to the
Current Class, below.
LINES WITH OTHER CLASSES AND WITHIN THIS CLASS
SYSTEM AND NETWORKS INCLUDING TWO OR MORE OF THE NETWORKS AS
DEFINED IN 1 - 8 OF THE CLASS DEFINITION
Such systems and networks which include two or more of the
networks or systems so that each has its own function, and
one is not merely part of the other, are classified in the
first occurring subclass and cross-referenced to the later
occurring subclass or subclasses. For instance, a filter
(subclasses 167+) combined with a wave shaper (subclass 20)
is classified in subclass 20 and cross-referenced to
subclasses 167+. Where the combinations of the plural
networks are useful as a third device having its own function
provided for in the schedule, the patent is classified in the
subclass providing for the third device. For example, the
combination of a resonator (subclasses 219+) and a long line
(subclasses 236+) which results in an interference
elimination device (subclass 12) would be classified in
subclass 12 and cross-referenced to subclasses 219+ and 236+
for novel resonator or long line structure if necessary.
Where one of the networks is only a part of another network,
the patent is classified on the basis of the combination and
cross-referenced if necessary for the part. For example, a
filter (subclasses 167+) including a long line element with
impedance matching (subclass 32) where the over-all function
of the network is filtering and not impedance matching, is
classified in subclasses 202+ and cross-referenced to
subclasses 33+ if necessary.
NETWORKS AND SYSTEMS WITH SPECIFIC SOURCE OF INPUT ENERGY
This class does not provide for the subject matter of the
class (Class Definition paragraphs 1-10 above) in combination
with a specific source of electromagnetic wave energy, such
as a microphone, which limits the system to use with a
particular art even though the source is recited by name
only. However, this class will take the systems and networks
of the class in combination with a source of wave energy
which is recited by its characteristics; for example, as
being composed of a band of frequencies with only odd
harmonics, or where the source is recited only as a general
class of wave energy generators, such as an oscillator, etc.,
where the specific characteristics and details of the source
are recited, such as specific oscillator system details, the
system or network is classified with the specific source.
NETWORKS AND SYSTEMS WITH SPECIFIC LOADS IN THE OUTPUT
CIRCUIT
This class does not provide for the subject matter of the
class (Class Definition, paragraphs 1 to 10 above) in
combination with a specific load device supplied with energy
by the system or network, even though the load device is
recited by name only (as a motor, loudspeaker, piezoelectric
crystal, etc.). Such systems and networks are classified with
the art which provides for the systems of supply for the
specific load device.
SYSTEMS AND NETWORKS AND COMPONENTS IN OTHER CLASSES GENERIC
TO THE SUBJECT MATTER OF THIS CLASS
See References to Other Classes below.
WAVE TRANSMISSION LINE AND NET WORKS ANALOGOUS TO THOSE IN
THIS CLASS, BUT WHICH ARE CLASSIFIED ELSEWHERE
See References to Other Classes.
TESTING AND MEASURING SYSTEMS FOR WAVE TRANSMISSION LINES AND
NETWORKS
This class (333) will take systems for determining the
electrical wave propagation characteristics of transmission
lines and networks falling within the class definition,
provided that significant details of the transmission line or
network are claimed. That is, merely claiming the line or
network by name only (e.g., as a transmission line, coupling
network or resonator) or characterizing it as a four terminal
or two terminal impedance network would not be sufficient
basis for classification in this class, classification would
then be in one of the classes indicated below, depending on
the nature of the test or measurement.
1. Long Telephone Lines:
Systems and apparatus for testing long telephone lines to
determine impedance irregularities, unbalance in loaded
lines, impedance versus frequency characteristics, impedance
versus delay characteristics, or other long telephone line
characteristics are classified elsewhere. See References to
Other Classes, below
2. Power, Voltage and/or Current Determination in Wave
Transmission Lines or Networks:
Apparatus for measuring the voltage or current, or the
voltage or current standing wave ratio, or power dissipation
in wave transmission lines are classified in elsewhere. See
References to Other Classes, below
3. Impedance Characteristic of Networks or Network
Elements:
Systems for determining the inductance, capacitance or
resistance, or any of these properties over a range of
frequencies, of four-terminal or two-terminal impedance
networks in general are classified in elsewhere. See
References to Other Classes, below
4. Wave Frequency Determination Systems:
Wave frequency determination systems having means giving a
direct quantitative indication of the frequency of electrical
currents are classified elsewhere. See References to Other
Classes, below.
Frequency meters which measure frequency by utilizing phase
shift networks are classified elsewhere. See References to
Other Classes.
5. Wave Meters:
Wave Meters for determining the wave length of electrical
waves are classified elsewhere.
6. Electromagnetic Radiation Field Strength Measurement:
Apparatus for measuring electromagnetic radiation field
strength is classified elsewhere. See References to Other
Classes.
7. Wave Analyzing Systems:
Devices for determining the individual frequency components
of a complex electric wave, and such devices which also
determine the amplitude or relative phase positions of the
different frequency components of the complex wave are
classified elsewhere. See References to Other Classes.
Speech wave analyzing devices are classified elsewhere. See
References to Other Classes.
CONDUCTOR STRUCTURE, ARRANGEMENTS AND COMPONENTS
See References to Other Classes below..
SYSTEMS UTILIZING WAVE TRANSMISSION LINES AND NETWORKS
See References to Other Classes.
SEE OR SEARCH THIS CLASS, SUBCLASS:
1 for plural channel systems wherein passive means, such as
wave filters, are employed to separate plural messages or
signals.
14 for amplitude compression and expansion systems
(companders).
213 for negative resistance and/or reactance networks of the
active element type.
REFERENCES TO OTHER CLASSES
SEE OR SEARCH CLASS:
84, Music, subclass 661, 699 or 736 for electrical tone
generating and music instruments with electric translating
devices including coupling networks or wave filters. (See
Lines With Other Classes, "Systems Utilizing Wave
Transmission Lines and Networks)
138, Pipes and Tubular Conduits, appropriate subclasses for
conduits (including wave guides) and conduit and pipe
accessories disclosed for electrical use even though the
conduit is made of or lined with metal or insulating material
unless there is claimed some structure or feature which
limits the same to electrical use in addition to mere pipe or
conduit structure. (See Lines With Other Classes, "Systems
and Networks and Components in Other Classes Generic to the
Subject Matter of This Class")
138, Pipes and Tubular Conduits, provides for conduit and
pipe structure and accessories. See Lines With Other
Classes, "Systems and Networks and Components in Other
Classes, Generic to the Subject Matter of This Class (and
related class references) above. (See Lines With Other
Classes, "Conductor Structure, Arrangements and Components")
174, Electricity: Conductors and Insulators, appropriate
subclasses for housings, conductor and conduit structure and
for conductor and conduit joint and end structure which
include electrical features and which are not defined as
having long line characteristics, and 137 for insulator
structures. See subclasses 32+ for conductor arrangements and
structures for preventing or reducing the detrimental effects
due to either the self-inductance of a single conductor or
mutual inductance between plural conductors, subclasses 27
and 113+ for parallel or twisted conductor structure,
subclasses 28+ and 102+ for coaxial and shielded cable
structure, subclasses 37+ for underground conductor
structure, subclasses 38, 43, 49, and 71+ for branched
electrical conductor structure, and subclasses 40+ for
overhead conductor structure. (See Lines With Other Classes,
"Systems and Networks and Components in Other Classes Generic
to the Subject Matter of This Class")
174, Electricity: Conductors and Insulators, provides for
conductor structure, insulator structure and transmission
accessories (e.g., boxes, shields, housing). (See Lines With
Other Classes, "Conductor Structure, Arrangements and
Components")
178, Telegraphy, subclass 45 provides for loaded lines and
all systems and networks analogous to the systems or networks
in this class (333) which include loaded lines. Subclasses
69+ includes patents relating to line clearing, circuit
maintenance and anti-inductive lines analogous to similar
systems in subclass 12 of Class 333. (See Lines With Other
Classes, "Wave Transmission Line and Net Works Analogous to
Those in This Class, etc.")
178, Telegraphy, subclass 46 provides for loading coils for
use with loaded lines. (See Lines With Other Classes,
"Conductor Structure, Arrangements and Components")
178, Telegraphy, for telegraph systems utilizing wave
transmission lines and networks, especially subclass 43, for
space induction radiation systems, subclasses 45+ for loaded
transmission line systems; subclass 49 for systems wherein
currents (signaling or otherwise) and telegraph signal
currents are superposed on the same transmission path,
subclass 63 for cable systems including means for correcting
for telegraph signal distortion caused by cable capacitance;
subclass 64 for wave transmission line systems including
mutual induction type coupling networks or transformers;
subclasses 66.1+ for alternating current systems, other than
harmonic or vibrating reed systems (for which see subclass
47); subclasses 66.1+ for pulsating current systems; and
subclass 69 for telegraph systems wherein wave transmission
networks are utilized to correct for the deleterious effects
of line charges and surges which may cause signal distortion.
(See Lines With Other Classes, "Systems Utilizing Wave
Transmission Lines and Networks")
191, Electricity: Transmission to Vehicles, 2 for
electrical transmission line systems and coupling means for
transmitting electric current between relatively movable
source and load and subclass 10 for systems wherein the
transmission of energy between the relatively movable source
and load is effected through an induction field coupling
means. (See Lines With Other Classes, "Systems Utilizing Wave
Transmission Lines and Networks")
200, Electricity: Circuit Makers and Breakers, appropriate
subclasses for electric switches of general utility and not
limited by claimed structure to use with long lines. (See
Lines With Other Classes, "Systems and Networks and
Components in Other Classes Generic to the Subject Matter of
This Class")
200, Electricity: Circuit Makers and Breakers, provides for
electric switches (See Lines With Other Classes, "Systems
and Networks and Components in Other Classes, Generic to the
Subject Matter of This Class (and related class references)
above). (See Lines With Other Classes, "Conductor Structure,
Arrangements and Components")
219, Electric Heating, wherein wave transmission lines or
coupling networks are employed in electrical heating systems.
Note 600 for inductive heating, subclasses 678+ for
microwave heating, and subclasses 764+ for capacitive
dielectric heating, subclasses 50+, especially subclasses
108+ and 130.1+ for metal heating systems, and subclasses
482+ for electrical heating systems in general. (See Lines
With Other Classes, "Systems Utilizing Wave Transmission
Lines and Networks")
246, Railway Switches and Signals, for wave transmission
networks that may be employed in railway electric signaling
and control, especially 7 for train telegraphy and telephony
used for train dispatching, subclass 30 for automatic block
signal systems controlled by hertzian waves, subclass 61 for
automatic block signal systems wherein the signal and
propulsion currents are superimposed, subclass 63 for cab
signal or train control systems wherein signals or control
currents are transferred between the train and the
transmission line by induction and subclasses 72, 81+ for
systems wherein the signaling energy is derived from the
propulsion current. (See Lines With Other Classes, "Systems
Utilizing Wave Transmission Lines and Networks")
250, Radiant Energy, subclass 250 and in Class 324,
Electricity: Measuring and Testing, subclasses 76.39+,
especially subclasses 76.41+ and 76.51, for determining the
wave length of electrical waves.
257, Active Solid-State Devices (e.g., Transistors,
Solid-State Diodes), subclasses 661-664. (See Lines With
Other Classes, "Conductor Structure and Within This Class,
Arrangements and Components")
307, Electrical Transmission or Interconnection Systems, for
miscellaneous transmission or interconnection systems not
otherwise classified. For example, Class 307 provides for
subject matter similar to that classified in Class 323 where
there are plural input circuits and/or plural output
circuits. Class 307 also provides for some systems which
include one or more long line elements where the system
includes an active element so that the system is excluded
from Class 333. See the pulse forming and wave shaping in
106 for example. Class 307 is also the miscellaneous class
for anti-inductive systems (see subclasses 89+). (See Lines
With Other Classes, "Systems and Networks and Components in
Other Classes Generic to the Subject Matter of This Class")
307, Electrical Transmission or Interconnection Systems, 147
is the miscellaneous subclass for conductor arrangements or
structure. (See Lines With Other Classes, "Systems and
Networks and Components in Other Classes, Generic to the
Subject Matter of This Class (and related class references)
above). (See Lines With Other Classes, "Conductor Structure,
Arrangements and Components")
307, Electrical Transmission or Interconnection Systems, is
the generic place for electrical energy distributing and/or
controlling and/or generating systems for which provision is
not made in any other electrical system class. By way of
example, provision is made for 1 for systems with
superimposed unlike currents, subclasses 11+ for plural load
systems, subclasses 43+ for plural supply circuits or
sources, subclasses 401+ for semiconductor (i.e., transistor)
electric or transductor system, subclasses 89+ for
anti-induction or coupling to other systems, subclasses 326+
for self protective, safety or limit control systems,
subclasses 98+ for combined impedance and switch systems,
subclass 103 for line drop compensation, subclass 104 for
electromagnet or highly inductive systems, subclass 105 for
harmonic filtering or neutralizing systems, subclasses 106+
for wave form, wave shaping or pulse producing systems,
subclasses 112+ for switching systems, subclasses 147+ for
conductor arrangements or structure, and subclasses 149+ for
miscellaneous systems. (See Lines With Other Classes,
"Systems Utilizing Wave Transmission Lines and Networks")
315, Electric Lamp and Discharge Devices: Systems,
particularly 4 for cathode-ray tubes having long line
elements or resonators structurally combined therewith,
subclass 39 for a space discharge device structurally
combined with wave guide, coaxial cable or resonant parallel
wire transmission line, and subclass 40 for space discharge
devices with an electrode formed as an inductive impedance
(e.g., magnetron). (See Lines With Other Classes, "Systems
Utilizing Wave Transmission Lines and Networks")
323, Electricity: Power Supply or Regulation Systems,
provides for miscellaneous transformer systems in subclass
355 and for miscellaneous impedance systems in subclass 364,
where the system or network has only a single input and a
single output. Class 323 also provides for the miscellaneous
systems for controlling the magnitude of the current and/or
the voltage and/or for controlling the phase in systems and
networks having only a single input and a single output
circuit where the same current is in the output as is in the
input. (See Lines With Other Classes, "Systems and Networks
and Components in Other Classes Generic to the Subject Matter
of This Class")
323, Electricity: Power Supply or Regulation Systems,
subclass 355 provides for the miscellaneous structural
arrangement of a transformer and other electrical devices
which are connected together, and subclass 364 provides for
the miscellaneous structural arrangements of impedance
elements, which are connected together to form a network.
(See Lines With Other Classes, "Conductor Structure,
Arrangements and Components")
324, Electricity: Measuring and Testing, for electrical
testing systems utilizing wave transmission networks or for
measuring impedance characteristics of electrical networks in
general, subclass 72, 95, 140+, and 612+ for electric power,
current and/or voltage measuring systems for systems
employing wave transmission lines or networks for determining
reflected power or standing wave amplitude ratios and
subclasses 76.77+ for electric phase angle measuring systems
including electric wave transmission lines or networks used
for time delay or coupling purposes. (See Lines With Other
Classes, "Systems Utilizing Wave Transmission Lines and
Networks")
324, Electricity: Measuring and Testing, 600 for Systems
for determining the inductance, capacitance or resistance, or
any of these properties over a range of frequencies, of
four-terminal or two-terminal impedance networks in general;
subclasses 76.77+ for phase shift or phase relations between
voltages or currents or voltage and current in electrical
systems in general.
324, Electricity: Measuring and Testing, 76.12 and 76.39+
for means giving a direct quantitative indication of the
frequency of electrical currents.
324, Electricity: Measuring and Testing, 76.52 for
frequency meters which measure frequency by utilizing phase
shift networks.
324, Electricity: Measuring and Testing, 76.11, for
apparatus for measuring electromagnetic radiation field
strength.
324, Electricity: Measuring and Testing, 76.12, for devices
for determining the individual frequency components of a
complex electric wave, and such devices which also determine
the amplitude or relative phase positions of the different
frequency components of the complex wave.
327, Miscellaneous Active Electrical Nonlinear Devices,
Circuits, and Systems, appropriate subclasses for
miscellaneous nonlinear circuits which may utilize an active
device such as a transistor or electron tube. (See Lines
With Other Classes, "Systems and Networks and Components in
Other Classes Generic to the Subject Matter of This Class")
327, Miscellaneous Active Electrical Nonlinear Devices,
Circuits, and Systems, appropriate subclasses for
miscellaneous circuits which may incorporate a transmission
line device. (See Lines With Other Classes, "Systems
Utilizing Wave Transmission Lines and Networks")
329, Demodulators, subclass 322 and 354+ for a demodulator
with distributed electrical parameters. (See Lines With Other
Classes, "Systems Utilizing Wave Transmission Lines and
Networks")
330, Amplifiers, appropriate subclasses, for one way
amplifiers utilizing wave transmission networks or filters
for input, output, or interstage coupling, particularly 53,
116, 117, 120+, 122, 157+, 185+, and 192+. (See Lines With
Other Classes, "Systems Utilizing Wave Transmission Lines and
Networks")
331, Oscillators, for oscillation generators utilizing wave
transmission lines and networks as elements thereof,
particularly subclass 5, 6+, 9, 79+, 86+, 93, and 96+ for
oscillator systems employing distributed parameter networks
or resonators, subclasses 110 and 138+ for oscillators
employing bridge networks, subclasses 86+, 115, 126+, and
132+ for oscillators of the negative resistance type,
subclass 135+ for oscillators employing phase shift networks,
subclasses 74+ for oscillators combined with a particular
output coupling network and subclasses 73, 116, 139, and 154+
for oscillators employing an electromechanical resonator.
(See Lines With Other Classes, "Systems Utilizing Wave
Transmission Lines and Networks")
332, Modulators, for modulation systems utilizing wave
coupling networks, long line sections or negative impedance
devices as elements thereof, particularly 129 and 138+ under
frequency modulators and subclasses 163+, 175 and 176+ under
amplitude modulators. (See Lines With Other Classes, "Systems
Utilizing Wave Transmission Lines and Networks")
334, Tuners, provides for tuners which are closely analogous
to the wave filters in this class. The tuners usually have
inductance and capacitance elements of the lumped type
together with means to vary either the inductance or
capacitance element or both in order to change the mean
resonant frequency of the tuner. The tuners in Class 334 may
include one or more long line elements in addition to a
lumped inductor or capacitor; or the tuner may consist of a
distributed parameter type tuning unit which is adjusted in
discrete, distinct steps; or where two or more distributed
parameter type tuning units are ganged together either
mechanically and/or electrically so as to have their mean
resonant frequency adjusted in unison. Where only the band
width of a filter is varied without varying the mean resonant
frequency, classification is in this class (333). (See Lines
With Other Classes, "Wave Transmission Line and Networks
Analogous to Those in This Class, etc.", "Systems and
Networks and Components in Other Classes, Generic to the
Subject Matter of This Class"; "Conductor Structure,
Arrangements and Components")
334, Tuners, appropriate subclasses for tuned networks for
use in wave energy apparatus and comprising inductance and
capacitance elements in circuit arrangement to form a
resonant circuit and in which structure is provided for
adjusting one or both of these elements for changing the mean
resonant frequency of the circuit. (See Lines With Other
Classes, "Systems Utilizing Wave Transmission Lines and
Networks")
336, Inductor Devices, appropriate subclasses for
transformers and inductors which are not designed to be
frequency responsive (e.g., not having points of resonance
within the range of frequencies over which the device is
designed to operate). (See Lines With Other Classes,
"Systems and Networks and Components in Other Classes Generic
to the Subject Matter of This Class; and "Conductor
Structure, Arrangements and Components")
338, Electrical Resistors, appropriate subclasses, for fixed
and variable electric resistors, per se. See (2) Note under
Class 333, subclass 22, for the distinction between the
resistors in Class 338 and the dissipating terminals for long
lines. (See Lines With Other Classes, "Systems and Networks
and Components in Other Classes Generic to the Subject Matter
of This Class)
338, Electrical Resistors, provides for fixed and variable
resistors. (See Lines With Other Classes, "Systems and
Networks and Components in Other Classes, Generic to the
Subject Matter of This Class (and related class references)
above). (See Lines With Other Classes, "Conductor Structure,
Arrangements and Components)
340, Communications: Electrical, for electrical
communication systems in general having wave transmission
lines and networks as elements thereof, particularly 825.37
for party line type selective systems, subclasses 825.57+ for
pulse responsive selective systems, subclass 825.70 for phase
responsive selective systems, subclasses 825.71+ for
frequency responsive selective systems, subclasses 825.77+
for amplitude responsive systems, subclasses 870.01+
continuously variable indication systems (e.g.,
telemetering), subclasses 286+ for miscellaneous signaling
systems, and subclasses 310.01+ for composite signaling
systems (e.g., signal over power line).
343, Communications: Radio Wave, for radio wave energy
systems which employ wave transmission lines and networks as
elements thereof, 5 for reflected or returned wave systems,
(e.g., object detection radar), subclasses 350+ for directive
systems (including polarization), subclasses 700+ for
antennas involving wave transmission lines and networks
including long line sections, usually resonant, designed to
act as space radiators or collectors of electromagnetic
waves. See (11) Note under subclass 700 of Class 343 for
classification lines between coupling networks and antennas
with such coupling networks. (See Lines With Other Classes,
"Systems Utilizing Wave Transmission Lines and Networks")
360, Dynamic Magnetic Information Storage or Retrieval, for
magnetic recorders or reproducers having wave transmission
networks as elements thereof. (See Lines With Other Classes,
"Systems Utilizing Wave Transmission Lines and Networks")
361, Electricity: Electrical Systems and Devices, 271 for
capacitors, subclasses 600+ for miscellaneous arrangements
for mounting two or more different circuit elements which are
not in circuit arrangement (including printed circuits), and
subclasses 503+ for electrolytic capacitors. (See Lines With
Other Classes, "Conductor Structure, Arrangements and
Components")
361, Electricity: Electrical Systems and Devices, 107 for
wave transmission networks for use in surge suppression
circuits, and subclasses 117+ for lightning arresters. (See
Lines With Other Classes, "Systems Utilizing Wave
Transmission Lines and Networks")
363, Electric Power Conversion Systems, particularly 2, 9+
and 36 for phase conversion systems (e.g., m-phase to
n-phase) combined with other types of conversion, subclasses
39+ for current conversion systems combined with means to
eliminate undesired frequency components (e.g., filter), and
subclasses 148+ for phase conversion systems, per se. (See
Lines With Other Classes, "Systems Utilizing Wave
Transmission Lines and Networks")
364, Electrical Computers and Data Processing Systems,
appropriate subclasses, (See Lines With Other Classes,
"Systems Utilizing Wave Transmission Lines and Networks)
365, Static Information Storage and Retrieval, appropriate
subclass for read/write static storage systems, particularly
subclass 194, 198, and 223 which include delay, transmission,
and bridge means for a read/write circuit. (See Lines With
Other Classes, "Systems Utilizing Wave Transmission Lines and
Networks")
367, Communication, Electrical: Acoustic Wave Systems and
Devices, 197 for selective systems which are sound
responsive. (See Lines With Other Classes, "Systems Utilizing
Wave Transmission Lines and Networks")
370, Multiplex Communications, appropriate subclasses for
multiplexing systems, particularly subclass 272 for a
sextuplex system, subclasses 273+ for a quadruplex system,
subclasses 276+ for a duplex system, and subclass 297 for a
diplex system. (See Lines With Other Classes, "Systems
Utilizing Wave Transmission Lines and Networks")
379, Telephonic Communications, 22 for systems and apparatus
for testing long telephone lines to determine impedance
irregularities, unbalance in loaded lines, impedance versus
frequency characteristics, impedance versus delay
characteristics, or other long telephone line
characteristics.
379, Telephonic Communications, subclass 398 includes loaded
line systems and anti-inductive systems analogous to the
subject matter of this class (333). (See Lines With Other
Classes, "Wave Transmission Line and Net Works Analogous to
Those in This Class, etc.")
379, Telephonic Communications, 443 provides for telephone
induction coils. (See Lines With Other Classes, "Conductor
Structure, Arrangements and Components")
379, Telephony, appropriate subclasses, especially 90 for
composite systems, employing wave transmission networks
wherein voice signal systems are combined with other
electrical systems, such as telegraph, power or lighting
systems (Note that this class (333) provides for plural
channel systems wherein passive means, such as wave filters,
are employed to separate plural messages or signals. (See
Subclass References to the Current Class, above)); subclass
78 for wave transmission networks used to compensate for or
prevent detrimental effects on telephone systems of internal
or external induction or radiation fields; subclass 79 for
such systems under subclass 78, utilizing capacitive
reactance for compensation and subclass 80, under subclass
78, wherein the compensation means comprises impedance coils;
subclass 81, for telephone substation circuits employing wave
coupling networks of the conjugate or Whetstone bridge type
and/or balancing networks; subclass 82 for space induction
radiation systems having wave transmission networks as
elements thereof, subclasses 170+ for telephone repeaters
(i.e., two-way amplifiers) utilizing hybrid networks and line
balancing networks; subclasses 172+ for coupling devices of
the induction coil type associated with telephone
instruments; subclass 174 for anti-induction devices
including wave transmission networks for preventing the
undesirable effects of induction in telephone systems or
instruments, other than those anti-induction devices in
subscribers circuits, for which see subclasses 78+, 81; and
subclass 175 for testing devices utilizing wave transmission
networks for telephone systems or devices, not particularly
subclasses 175.3+ under subclass 175 for testing long
telephone lines and associated apparatus.
439, Electrical Connectors, provides for miscellaneous
connector structure (see 55 for preformed or printed circuit
arrangements involving only conductors and connector
structure). (See Lines With Other Classes, "Conductor
Structure, Arrangements and Components")
455, Telecommunications, appropriate subclasses for filters
analogous to those in this class and forming an element of
radio communication systems. (See Lines With Other Classes,
"Wave Transmission Line and Net Works Analogous to Those in
This Class, etc.")
455, Telecommunications, 334 for miscellaneous circuitry and
apparatus which are specialized to use with radio apparatus.
(See Lines With Other Classes, "Conductor Structure,
Arrangements and Components")
455, Telecommunications, 39 provide for modulated carrier
wave systems of general application; subclasses 91+ provide
for transmitters employing wave transmission lines, wave
guides and networks for coupling the transmitter to an
antenna; subclasses 130+ for radio receiver coupling and
selecting networks, see particularly subclasses 132+, 3.1+
and 272+ for plural channel systems; subclasses 280+ for
means for coupling antennas to radio receivers; subclasses
150+ for frequency selection networks; subclass 307 for
filter means for noise elimination; and subclasses 338+ for
miscellaneous coupling means. (See Lines With Other Classes,
"Systems Utilizing Wave Transmission Lines and Networks")
505, Superconductor Technology: Apparatus, Material,
Process, 150 for high temperature (T[subscrpt]c[end
subscrpt] 30 K) superconducting devices, and particularly
subclasses 210+ for transmission line and networks,
electrical energy storage devices, magnetic coils, wires,
cable, etc. (See Lines With Other Classes, "Systems and
Networks and Components in Other Classes Generic to the
Subject Matter of This Class")
505, Superconductor Technology: Apparatus, Material,
Process, 150 for high temperature (T[subscrpt]c[end
subscrpt] 30 K) superconducting devices, and particularly
subclasses 210+ for transmission line and networks,
electrical energy storage devices, magnetic coils, wires,
cable, etc. (See Lines With Other Classes, "Wave
Transmission Line and Net Works Analogous to Those in This
Class, but Which Are Classified Elsewhere")
505, Superconductor Technology: Apparatus, Material,
Process, 150 for high temperature (T[subscrpt]c[end
subscrpt] 30 K) superconducting devices, and particularly
subclasses 210+ for transmission line and networks,
electrical energy storage devices, magnetic coils, wires,
cable, etc. (See Lines With Other Classes, "Conductor
Structure, Arrangements and Components")
505, Superconductor Technology: Apparatus, Material,
Process, 150 for high temperature (T[subscrpt]c[end
subscrpt] 30 K) superconducting devices, and particularly
subclasses 210+ for transmission line and networks,
electrical energy storage devices, magnetic coils, wires,
cable, etc. (See Lines With Other Classes, "Systems Utilizing
Wave Transmission Lines and Network"s)
703, Data Processing: Structural Design, Modeling,
Simulation, and Emulation, subclasses 13-22 for the
simulation of electronic device or electrical system.
704, Data Processing: Speech Signal Processing, Linguistics,
Language Translation, and Audio Compression/Decompression,
200, for speech wave analyzing devices.
708, Electrical Computers: Arithmetic Processing and
Calculating, subclass 818 for correlation or convolution
with tapped delay line, and subclass 819 for electrical
analog filtering devices.
GLOSSARY:
ACTIVE NETWORK
A network containing a source of energy, or a sink of energy
(i.e., a device for absorbing or dissipating energy other
than that accounted for by the resistance of the components
of the networks). Merely dissipating the heat generated by a
resistance will not cause the resistance to be an active
element.
AMPLITUDE RANGE
The ratio of the highest amplitude to the lowest amplitude of
an undulating wave.
AMPLITUDE RANGE COMPRESSOR
A nonlinear device having an input and an output, the
amplitude range of the output wave being less than the
amplitude range of the input wave.
AMPLITUDE RANGE EXPANDER
A nonlinear device having an input and an output, the
amplitude range of the output wave being larger than the
amplitude range of the input wave.
ARTIFICIAL LINES
Networks for simulating impedance characteristics of a smooth
or loaded electrically long transmission line over a
frequency range.
ATTENUATOR
Devices and networks consisting of one or more elements which
exhibit only a positive resistance effect and which reduce
the intensity of the energy passing through the device by
dissipation, (a) the elements being proportioned to permit a
change in their value to control the energy loss while
maintaining substantially constant input and/or output
impedance of the device, and/or (b) the elements being
proportioned to permit the device to be inserted in the
circuit to provide an energy loss without introducing any
reflections in the circuit, and/or (c) the elements being
combined with a long line or long line element, and/or (d)
the device or network having an impedance equal to the
impedance of a specified long line, and/or (e) the device or
network is claimed as being particularly modified for use
over a frequency band so that its characteristics are
particularly related to frequency.
BALANCED CIRCUIT
A circuit having its conductors electrically symmetrical with
respect to a reference potential plane (e.g., ground). The
potentials between the two sides and ground are equal and of
opposite sign. For example, a horizontal two wire line may
be a balanced line.
CHARACTERISTIC IMPEDANCE
The impedance which a long line or a long line element would
have if it were infinitely long. A long line which is
terminated in its characteristic impedance is not resonant.
COMPANDER
An amplitude range compressor connected to an amplitude range
expander with or without an intervening transmission line so
that the amplitude range of the input wave is first decreased
in the compressor and then increased in the expander.
COUPLING NETWORKS
(a) Networks including significant reactive structure for
effecting the transfer of oscillatory energy from one circuit
to another circuit and having attenuation and/or delay
characteristics over a frequency range for attenuating and/or
delaying in a predetermined manner wave energy passing
therethrough, and/or providing an impedance match between the
network and at least one of the circuits; (b) smoothing type
wave filters having shunt capacitance, or series inductance,
or both usually designed to pass direct current and to reduce
the effect of any undesired alternating or pulsating current,
or to pass direct current and low frequency alternating
current or pulsating current and to reduce the effect of any
undesired higher frequency alternating or pulsating current.
DELAY
Includes phase distortion and also includes the retardation
of a single pulse with respect to time.
DELAY NETWORK
Networks including significant structure for retarding wave
energy a predetermined period of time over a range of
frequencies.
DISSIPATING TERMINATIONS: (FOR LONG LINES)
Networks specialized for use with and designed for connection
to the end of a long line transmission line and including a
resistive component for dissipating the wave energy
propagated along the line and presenting an essentially
resistive impedance to the line.
DISTRIBUTED PARAMETERS
When the impedance of a transmission device or line at the
operating frequency or band of frequencies is due primarily
to the parameters of the device or line itself, and in
considering the inductance, capacitance and resistance of the
device or line they must be considered as mixed together and
spread out along the device or line rather than being
considered as in separate discrete lumps or devices as in the
case of simple series and parallel circuits, the transmission
device or line ay be said to have distributed parameters.
Examples of circuits with distributed parameters include
telephone, telegraph and power lines for high frequency
energy.
EQUALIZER
Networks with attenuation or attenuation and phase distortion
characteristics which vary over a frequency range for use in
a wave transmission system for modifying the attenuation or
attenuation and phase characteristics of the wave energy as a
function of frequency.
FREQUENCY RESPONSIVE NETWORK
As the frequency of the applied energy changes over a band,
the impedance of the network varies as a function of the
frequency. Frequency responsive networks and devices are
designed to obtain desired characteristics where a band of
frequencies or different frequencies are involved.
HYBRID TYPE NETWORK
A network for coupling one wave transmission line to two or
more wave transmission lines in such manner that there is a
conjugate relation between at least two of these coupled
transmission lines to prevent any interchange of energy
between the conjugately related lines.
IMPEDANCE MATCHING NETWORK
Coupling networks which include one or more impedance
elements construed or proportioned to substantially eliminate
the reflected wave energy between the network and at least
one of the connected circuits caused by impedance
differences.
LOADED LINES
A long line to which lumped impedance elements, usually
capacitors or inductors, are added at regularly spaced points
along the length thereof, or to which an added impedance is
applied in a continuous manner, as for example, by wrapping a
strip of magnetic material about the line or device to
increase the inductance of the line or device.
LONG LINE
A wave transmission device or line having distributed
parameters and especially designed to propagate electrical
wave energy where the wave length of the transmitted energy
is relatively short when compared with the length of the
transmission line or device. The impedance of a long line is
practically fixed by the constants of the line itself. The
length of the transmission line or device may be a multiple
or a fraction of a wave length, e.g., 1/4, 1/2, etc., or
otherwise have its length proportioned to the wave length of
the energy with which it is to be used.
LONG LINE ELEMENT
A circuit element having distributed parameters, such as a
resonator, or a wave guide. A long line element may be a
part of a long line wave transmission device or used in a
network with other circuit elements of the lumped parameter
type, for example, as in the case of delay networks,
impedance matching networks, wave filters.
LUMPED PARAMETERS OR IMPEDANCES
When the impedance of a transmission line or device at the
operating frequency may be considered as equivalent to
devices concentrated at one point, and the parameters of the
system including the line or device is not substantially
independent of the load devices connected thereto, the
transmission line or device may be said to have lumped
parameters. Lumped impedances is also used to include
devices such as capacitors, inductors, and resistors which
have their impedance concentrated at the terminals thereof.
NETWORK
A network is made up of two or more resistances, inductances,
capacities or mutual inductances connected together in some
manner.
PASSIVE NETWORK
A network containing no source of energy and in which no
energy is dissipated other than that accounted for the
resistance of the components of the network.
PHASE DISTORTION
Results from different frequencies travelling with different
velocities such that their relative arrival times differ from
their relative starting times.
PHASE DISTORTION CHARACTERISTIC
Used to designate the change in displacement of different
frequency components of a band of frequencies transmitted by
a transmission device or network. For example, certain
frequencies of the band will be retarded or advanced a
different amount than other frequencies.
PHASE SHIFT
Used to designate the change in phase relation between
voltage and current of the same wave energy, or between the
voltages or the currents of different wave energy of the same
frequency.
RESONATOR
Devices comprising conductive enclosures, cavities, or wave
transmission line sections of the two terminal type, and
having distributed inductance and capacitance, the line
sections being terminated in other than the characteristic
impedance of the line sections, the devices presenting
resonant characteristics to the existing source of wave
energy.
TAPERED LONG LINE
A long line having a physical dimension which changes
progressively in the direction of wave propagation along the
line.
TRANSMISSION LINE
As used in the subclass definitions is synonymous with wave
transmission devices.
UNBALANCED CIRCUIT
A circuit having its conductors electrically unsymmetrical
with reference to a potential plane. For example, a
concentric line is ordinarily unbalanced, the outer conductor
being ordinarily connected to ground.
WAVE ENERGY
An undulatory disturbance propagated through a medium,
(usually periodic in nature), its displacement varying
periodically with respect to time or distance or both. The
wave may be manifested in electrical, mechanical or
acoustical form. However, in this class the term "wave
energy" refers only to electrical wave energy.
WAVE FILTER
Coupling networks which include significant structure
permitting free transmission of electric waves of a single
frequency or band of frequencies (which may include zero
frequency) while attenuating substantially electric waves
having other frequencies, or attenuating substantially
electric waves of a single frequency or band of frequencies
(which may include zero frequency) while permitting free
transmission of electric waves having other frequencies.
WAVE GUIDE
A transmission device designed to propagate electrical waves
having an electric or magnetic field component extending in
the direction of propagation. The wave guide may be a hollow
dielectric or metal tube, or a solid dielectric rod, the wave
energy being propagated along the interior of the tube or rod
and confined by the walls of the tube or rod.
WAVE PROPAGATION CHARACTERISTIC
Effect of the impedance characteristic of the transmission
device upon the wave energy propagated by the transmission
device, (e.g., the effect of transmission device or network
to change the amplitude, phase of or delay in transmission as
a function of frequency). Changes in the impedance
parameters of the transmission device or in impedances
associated therewith change the wave propagation
characteristics of the transmission device.
WAVE SHAPING
Passive networks for modifying an electrical wave passing
therethrough so that the amplitude-time characteristic of the
output wave is different from that of the input wave and
which have no function classified in other classes.
WAVE TRANSMISSION DEVICE
Any device which is used to guide or constrain electrical
wave energy and to convey the energy from one place to
another. Included are conductors, wave guides, resonant
structures (e.g., cavities, etc.)
WAVE TRANSMISSION SYSTEM
One of more wave transmission devices with or without
appropriate coupling networks or transmission line
characteristic modifying means arranged to convey electrical
energy from one or more places to one or more other
physically separated places. The system may be arranged so
that different electrical energies may be conveyed in
different directions at the same or different times over the
system.
WAVE TRAP
A resonant circuit designed to exclude the energy of one
particular frequency. It is analogous to a filter which is
used to block one frequency and to pass other frequencies.
It usually has circuit components equivalent to a filter, but
may be used only to exclude energy of a particular frequency
from a circuit.
SUBCLASSES
Subclass:
1
This subclass is indented under the class definition.
Systems comprising (a) two or more wave transmission lines or
networks, each line or network being operable to separately
propagate wave energy or (b) means for effecting an
interchange of wave energy from one transmission line to two
or more transmission lines or vice versa, or having a
coupling network for effecting an interchange of wave energy
from a single input to plural outputs or vice versa, together
with means for controlling or facilitating the interchange of
energy.
(1) Note. The term "network" as used above denotes any of
the systems defined in the Class Definition, subsection A.
(2) Note. Included in (a) above are systems having two
distinct transmission lines, each line being operable to
transmit wave energy electrically distinct from that
propagated by another of the transmission lines, and also
lines which are distinct but not necessarily simultaneously
usable to transmit electrical wave energy (e.g. one line may
be used to substitute for another as in subclass 3). The two
or more transmission lines may have a common conductor, see
especially subclasses 4+ where a balanced circuit is
involved.
(3) Note. Included are lines which transmit energy from a
first point to a second spaced point and provided with means
to transmit a portion of the energy to a second line (e.g. a
tapped line).
(4) Note. This and the indented subclasses do not provide
for systems where a signal is divided among two transmission
lines or networks and then recombined on a single line or to
provide a single output. Such systems and networks are found
in subclasses 12 et seq. If the system claimed does not
extend to the recombining part of the line or network, the
patent is classified in this or the indented subclasses.
(5) Note. A system having a single transmission line and
pilot line to sense only ambient conditions (temperature,
humidity) is not classified as a plural channel system. See
subclass 15 for this subject matter. A system with a single
communication transmission line and also a pilot line which
is a long line within the class definition and which
transmits wave energy is classified in this or indented
subclasses.
SEE OR SEARCH THIS CLASS, SUBCLASS:
15 see (5) Note above.
SEE OR SEARCH CLASS:
174, Electricity: Conductors and Insulators, appropriate
subclasses for electrical conductor structure adapted for use
in plural channel systems other than loaded lines or
transmission lines defined as having long line
characteristics.
178, Telegraphy, appropriate subclasses for plural channel
systems involving telegraphy, note subclass 45 for plural
channel systems using a loaded line.
307, Electrical Transmission or Interconnection Systems,
particularly 11, 43+, 113+, and 147+ for miscellaneous
electrical distribution systems involving plural channels.
330, Amplifiers, subclass 295 for plural channel transistor
amplifiers, subclass 69 for sum and difference amplifiers,
subclasses 73 and 74 for series arranged amplifiers with
plural outputs and plural inputs, respectively, subclass 84
for plural channel amplifiers having feedback, subclasses
124+ for plural channel amplifiers generally, subclasses 147
and 148 for amplifiers having plural inputs and plural
outputs, respectively. See especially, subclasses 54 and
286+ for "distributed amplifiers".
334, Tuners, appropriate subclasses for tuners, per se.
439, Electrical Connectors, particularly 775, 865+, 869+,
874+, 877+, 883, and 884+ for various types of electrical
connections and terminals.
340, Communications: Electrical, appropriate subclasses for
miscellaneous electrical communications, including signalling
systems, involving plural channels. Note particularly 870.11,
and 870.41, and 870.27 for continuously variable indication
communication systems involving plural transmitters, plural
receivers, and plural circuits respectively.
343, Communications: Radio Wave, particularly subclass 771
for plural slot type antennas with wave guide coupling;
subclasses 814 and 816 for plural balanced doublet type
antennas with a coupling network; subclass 852 for antennas
with a plural path coupling network with impedance matching;
subclasses 853+ for plural antennas with a coupling network;
and subclass 858 for antennas coupled to plural leadins.
370, Multiplex Communications, subclass 200 for a phantom
circuit, and subclass 308 for a resonant transfer technique
used in the multiplex system.
379, Telephonic Communications, appropriate subclasses for
plural channel systems involving telephony, see 338 for
circuits having a two-way repeater (amplifiers) therein.
455, Telecommunications, 39 for plural channel modulated
carrier wave systems; subclasses 91+ for transmitters;
subclasses 130+ for plural channel systems in radio
receivers; see particularly subclasses 132+ for plural
separate receivers; subclasses 3.1+ for distribution systems;
and subclasses 272+ for plural separate collecting means.
Subclass:
1.1
This subclass is indented under subclass 1. Systems which
include gyromagnetic elements for effecting a nonreciprocal
interchange of electrical energy among the transmission lines
or through the coupling network.
(1) Note. The term "gyromagnetic" as applied to material
designates magnetically polarized material (e.g., ferrites,
garnets, ionized gases) having unpaired spin systems which
exhibit significant precessional motion in an orthogonal R.F.
field. The term "nonreciprocal" designates a particular
interchange of electrical energy that does not satisfy the
reciprocity theorem. For example, a nonreciprocal
interchange exists when the electrical output at a first set
of terminals of a network produced by an input at a second
set of terminals of the network does not equal the output at
the second set of terminals produced by the same input
applied at the first set of terminals. The term "circulator"
(to which most of the patents in this subclass pertain)
designates a device with at least three terminals wherein
power entering at terminal 1 exists at terminal 2 only, power
entering at terminal 2 exists at terminal 3 only, and power
entering at terminal 3 exists at terminal 1 only.
SEE OR SEARCH THIS CLASS, SUBCLASS:
24.1 24.2 and 24.3, for single channel coupling networks
including gyromagnetic material for effecting a nonreciprocal
transfer of electrical energy.
SEE OR SEARCH CLASS:
330, Amplifiers, subclass 4, 4.8 and 63 for amplifiers using
gyromagnetic elements.
455, Telecommunications, 318, for mixers using gyromagnetic
elements.
Subclass:
2
This subclass is indented under subclass 1. Plural channel
systems having means to sense a condition in the system and
to control the operation of the system in accordance with the
condition so sensed.
SEE OR SEARCH THIS CLASS, SUBCLASS:
17 and the subclasses specified in the notes thereto for
single channel automatically controlled systems and
networks.
SEE OR SEARCH CLASS:
307, Electrical Transmission or Interconnection Systems,
particularly subclass 39, 86+, 116+, and 326+ for
miscellaneous plural channel electrical transmission or
interconnection systems which involve automatic control.
323, Electricity: Power Supply or Regulation Systems,
subclasses 234-303 for condition sensing regulators.
Subclass:
3
This subclass is indented under subclass 2. Systems
comprising at least one normally operative wave transmission
line and a spare transmission line, and automatically
operable means associated with the transmission lines for
using the spare transmission line in place of the normally
operative transmission line upon failure of the normally
operative line.
(1) Note. Systems for automatically substituting a
particular device or system for a normally operative device
or system are in general classified with the particular
device or system. For example, systems for substituting
repeaters in a two way repeater system are classified in
Class 379, Telephonic Communications, subclasses 338+ and
systems for substituting for defective amplifier system or a
part of an amplifier system (such as a vacuum tube) are
classified with the amplifier systems in Class 330,
Amplifiers, subclasses 84 and 124+.
SEE OR SEARCH THIS CLASS, SUBCLASS:
13 for resonator type breakdown discharge systems which
control the transmission over a line.
100 for branched circuits with nonautomatic transmission
line switching.
262 for transmission line elements, which may include
switching devices.
SEE OR SEARCH CLASS:
307, Electrical Transmission or Interconnection Systems,
particularly subclass 23, 39, 64+, and 80+ for miscellaneous
electrical systems of distribution which involve automatic
substitution of electrical load circuits or supply circuits.
331, Oscillators, subclass 49 for plural oscillator systems
wherein one oscillator may be substituted for another.
Subclass:
4
This subclass is indented under subclass 1. Systems wherein
at least one of the transmission lines is a balanced line, or
having a network under subclass 1 which is especially
designed for connection to at least one balanced circuit.
(1) Note. A balanced line or circuit is a line or circuit
having its conductors electrically symmetrical with respect
to a reference potential plane (e.g. ground).
SEE OR SEARCH THIS CLASS, SUBCLASS:
12 for transmission line inductive or radiation interference
reduction systems, involving a balanced transmission
circuit.
25 for coupling networks for coupling a single channel
balanced circuit to an unbalanced circuit.
236 for single transmission lines of the long line type,
which may be balanced.
SEE OR SEARCH CLASS:
174, Electricity: Conductors and Insulators, particularly
32, 37+, 40+, and 68.1+ for electrical conductor structure of
the electrically balanced type other than loaded lines or
transmission lines defined as having long line
characteristics.
307, Electrical Transmission or Interconnection Systems,
particularly 12, 42 or 147+ for miscellaneous electrical
transmission or interconnecting systems which include
balanced circuits.
343, Communications: Radio Wave, subclass 814 and 816 for
plural balanced doublet antennas with coupling networks; and
subclass 865 for a balanced antenna with a balanced coupling
network.
363, Electric Power Conversion Systems, particularly 2, 9+,
36, and 148+ for balanced phase conversion systems for
converting electrical energy from one number of phases to a
different number of phases (e.g., single phase to
polyphase).
365, Static Information Storage and Retrieval, subclass 202
for complementing or balancing signals used in a read/write
circuit.
370, Multiplex Communications, subclass 200 for a phantom
circuit used in the multiplex system, and subclasses 278 and
282+ for a duplex system which may include a balance
circuit.
379, Telephonic Communications, for telephone systems which
involve balanced transmission lines.
Subclass:
5
This subclass is indented under subclass 4. Systems having a
plurality of balanced transmission lines or having a network
which is designed for connection to a plurality of balanced
circuits.
SEE OR SEARCH THIS CLASS, SUBCLASS:
25 for coupling networks for coupling a single channel
balanced circuit to an unbalanced circuit.
Subclass:
12
This subclass is indented under the class definition.
Subject matter including a transmission line producing
inductive or radiation interference or subject to such
interference from an external source and means such as one or
more filters, screens or compensating circuits, disposed
along an appreciable length of the line for substantially
reducing this interference.
(1) Note. Subclass 12 does not include mere echo or
anti-singing systems. Such systems in a single channel system
where classified in this class are classified with the first
occurring (lowest numbered) subclass providing for any of the
components used in the system. For echo-suppressing and/or
anti-singing systems in plural channel systems, see
subclasses 406+ of Class 379, Telephonic Communications.
SEE OR SEARCH THIS CLASS, SUBCLASS:
5 for plural channel systems, which are balanced to prevent
undesired radiation effects.
24 for networks which may be used to reduce undesired
currents in a transmission line, and particularly subclasses
138+ for balanced circuits coupled to unbalanced circuits and
subclasses 165+ for wave filters and for transmission lines
connected to filters which block such undesired currents.
236 for long line transmission line structure which
inherently reduce interference radiation effects and which
involve no shielding structure or means in addition to the
conductor arrangement or structure (e.g. co-axial lines), see
especially subclasses 243+.
SEE OR SEARCH CLASS:
174, Electricity: Conductors and Insulators, 32 and the
subclasses specified in the notes thereto for structure and
conductor arrangements for preventing or reducing the
detrimental effects due to either self-inductance of a single
conductor or mutual inductance between plural conductors,
other than loaded lines or transmission lines defined as
having long line characteristics.
178, Telegraphy, subclass 45 for loaded lines with inductive
or radiation reduction means, subclass 63, for cable or long
line telegraph systems having means for eliminating
"tailings" or having static compensation; and subclass 69 for
telegraph line clearing and circuit maintenance systems
having means for preventing the detrimental effects produced
by induction from external or internal causes.
307, Electrical Transmission or Interconnection Systems, 89
for miscellaneous electrical systems having anti-induction
means or means to prevent undesired coupling to other
systems.
331, Oscillators, subclass 67 for oscillator systems
provided with an electromagnetic or electrostatic shield.
343, Communications: Radio Wave, 841 for antennas with an
electrical shield; subclass 851 for antennas with a coupling
network having a radiation suppressor; and subclass 905 for
antennas combined with shielded transmission lines.
361, Electricity: Electrical Systems and Devices, 1 for
transmission lines with means to protect the connected lines
from the effects of lightning and other high potential, and
for networks for use in surge suppression circuits, see
especially subclass 50 for systems with means to adjust for
varying leakage currents; subclasses 82 and 84+ for systems
for protecting balanced electrical systems (e.g., polyphase)
for balanced current flowing therein; subclasses 88+ for
voltage responsive systems; subclass 111 for transient
responsive systems; and subclasses 177+ for high voltage
dissipation systems (e.g., lightning arresters).
365, Static Information Storage and Retrieval, subclass 198
for transmission lines used for reading and writing
information.
379, Telephonic Communications, subclass 398, for telephone
systems having means for preventing the detrimental effects
occasioned by induction from external or internal causes.
Subclass:
13
This subclass is indented under the class definition.
Systems which include a resonant device and a space discharge
structure positioned at a point of high potential on said
resonant device, the space discharge structure breaking down
in response to energy above a predetermined level in a
transmission line connected to the resonant device to modify
the effective electrical characteristics of the resonant
device so as to block substantially the flow of any energy
over the transmission line, free passage of energy occurring
over the line when the energy fails to attain this
predetermined level.
SEE OR SEARCH THIS CLASS, SUBCLASS:
2 for plural channel systems which include a resonator type
breakdown discharge system for substantially blocking a
channel where the discharge device is made conductive by a
high energy level in the transmission line, and subclasses
100+ where the discharge device is made conductive by energy
other than the energy in the transmission line.
2 14, 15, 16, 17+, and 81, for other systems within the class
definition which reduce the amplitude of the wave energy but
which do not involve the use of a resonator type breakdown
discharge device.
262 for transmission line elements and components which
perform a switching or blocking function, other than
resonator type breakdown discharge systems.
SEE OR SEARCH CLASS:
313, Electric Lamp and Discharge Devices, 567 for
miscellaneous gaseous discharge device structure, including
lightning arresters, and subclasses 324 and 325 for lightning
arresters of the spark or arc type which operate in the open
air.
315, Electric Lamp and Discharge Devices: Systems, subclasses
32-371 for miscellaneous gaseous discharge systems and
particularly subclass 39 for the structural combination of a
discharge device and a resonant device, i.e., combined in an
integral or nonseparable manner.
323, Electricity: Power Supply or Regulation Systems,
subclasses 304-317 for self-regulating systems.
327, Miscellaneous Active Electrical Nonlinear Devices,
Circuits, and Systems, 365 for miscellaneous gating circuits
which utilize electron tubes.
361, Electricity: Electrical Systems and Devices, 1 for
miscellaneous systems for protecting electrical apparatus by
opening a circuit or making a shunt or short circuit when the
current exceeds a predetermined value, see especially
subclass 112 where the system includes electronic tubes, and
subclasses 117+ for lightning arrester systems which include
an arc discharge device.
455, Telecommunications, 78 for T-R or R-T radio systems.
Subclass:
14
This subclass is indented under the class definition.
Networks including a non-linear device for decreasing the
amplitude range of the signal applied to the device, and a
nonlinear device connected to receive the wave having the
decreased amplitude range for increasing or restoring the
amplitude range of the signal, and long line transmission
lines in combination with such networks.
(1) Note. This subclass provides for amplitude compression
and expansion systems even though the system includes an
active element such as a vacuum tube type amplifier. See (3)
Note below.
(2) Note. This subclass does not include devices which
merely shift the amplitude level up or down merely to control
the peak amplitude without controlling the amplitude range.
Neither does this subclass include the combination of a
limiter or clipper and an amplifier which cuts off the higher
amplitudes and then amplifies the remaining portion of the
wave energy so that the output wave does not contain any
variations in wave form above a certain amplitude level, and
is not therefore a function of the input wave energy.
(3) Note. In the compressor portion of the compander, the
input waves of smaller amplitudes may be increased in
amplitude while the input waves of larger amplitude may be
increased by a smaller ratio or decreased. All amplitudes of
the wave may be decreased, the larger amplitudes being
decreased to a smaller extent. The expander portion may
operate in a similar manner except to increase the amplitude
range.
SEE OR SEARCH THIS CLASS, SUBCLASS:
20 for miscellaneous passive type wave shaping networks
which modify the amplitude time characteristic of the signal
transmitted therethrough.
81 for the attenuator network in this class which reduces
the energy of the signal passing therethrough.
SEE OR SEARCH CLASS:
178, Telegraphy, subclass 45, for loaded lines in combination
with a compander.
327, Miscellaneous Active Electrical Nonlinear Devices,
Circuits, and Systems, 309 for a miscellaneous limiter with
an amplifying circuit.
330, Amplifiers, subclass 96, 123 and 129+ for amplitude
range compressors or expanders of the amplifier type where
the input signal is applied to a control grid of an amplifier
tube whose bias is controlled in accordance with the signal
intensity to produce the necessary compression or expansion,
and wherein the output signal is abstracted from the plate of
the amplifier tube. Subclasses 143 and 144+ for compressors
or expanders where a variable impedance element is included
in the signal path and the variable impedance is controlled
in accordance with the signal intensity. The combination of
an amplitude compressor and expander (i.e., a compander) one
or both being of the amplifier type is classified in this
class, (333) subclass 14. However, where such combinations
involve correction only of an amplifier condition and not a
condition of the transmission line, classification is with
amplifiers Class 330. Combinations of an amplifier and a
limiter where the output more substantially conforms to the
input wave form are classified in Class 330. See Class 250,
subclass 27, above.
369, Dynamic Information Storage or Retrieval, subclass 133
for phonograph recording and reproducing systems involving
amplitude range compression and expansion.
370, Multiplex Communications, subclass 202 for a multiplex
system which includes an amplitude compression or expansion
means.
381, Electrical Audio Signal Processing Systems and Devices,
subclass 106 for one-way audio signal transmission having
amplitude compression/expansion.
704, Data Processing: Speech Signal Processing, Linguistics,
Language Translation, and Audio Compression/Decompression,
500 for systems changing the frequency range of a band of
audio signal frequencies, transmitting the energy at the
changed range, and restoring the transmitted audio signal to
its original frequency range.
Subclass:
15
This subclass is indented under the class definition.
Systems including an auxiliary line so structurally related
to a transmission line that a change in the transmission line
characteristics caused by a change in an ambient condition,
such as temperature or humidity, will be accompanied by a
change in a parameter of the auxiliary line, and means
controlled by this change in parameter to compensate for the
change in transmission line characteristics.
SEE OR SEARCH THIS CLASS, SUBCLASS:
2 for plural channel systems including a pilot line.
16 for systems utilizing a pilot current for purposes of
control.
SEE OR SEARCH CLASS:
323, Electricity: Power Supply or Regulation Systems,
subclass 294 for impedance systems in general which are
automatically controlled in response to a thermal condition.
330, Amplifiers, subclass 52, for amplifier systems having
control means, wherein the control is exercised by a pilot
signal. See the Class Definition of Class 330 for the line
between this class (333) and Class 330 where pilot signals
are involved.
379, Telephonic Communications, 338 for repeater systems
(e.g. two way amplifier system) which utilize a pilot line to
compensate for changes in the transmission characteristics of
the main line.
Subclass:
16
This subclass is indented under the class definition.
Systems including means for compensating for changes in the
signal energy passing over a transmission line caused by
changes in the line characteristics, wherein a control signal
distinct from and in addition to the signal energy is also
passed over the line to be influenced by the changes in line
characteristics, the control signal being used to control the
compensating means.
(1) Note. Systems for automatically compensating for
changes in the characteristics of a transmission line where
the carrier current of the transmitted energy is used to
control the compensating means are classified in subclasses
17+.
SEE OR SEARCH THIS CLASS, SUBCLASS:
2 for plural channel systems utilizing a pilot frequency.
15 for systems utilizing for a pilot line for control
purposes.
17.1 see (1) Note above.
SEE OR SEARCH CLASS:
330, Amplifiers, subclass 52 for amplifier systems having
pilot signal control means. See Class 330, Class Definitions
for the line between the two classes where such subject
matter is involved.
379, Telephonic Communications, 338 for repeater systems
(e.g., two way amplifier system) which may utilize a pilot
current to compensate for changes in the transmission
characteristics of the main line.
Subclass:
17.1
AUTOMATICALLY CONTROLLED SYSTEMS:
This subclass is indented under the class definition.
Subject matter having means to sense a condition in the
system and to modify a wave propagation characteristic of the
system in accordance with the condition so sensed.
(1) Note. The automatic control must be of the wave
propagation characteristic of a transmission line, system or
network which would be classified in this class. Where the
system or network includes a component or device which, per
se, is not classified in the class, combined with a
transmission line, system or network which causes
classification of the subject matter in this class, and the
automatic control is only with respect to such component or
device which is classified, per se, in another class. Then
the patent is not classified in this or the indented
subclass, but is classified in subclass providing for the
subject matter claimed. For example, a wave filter combined
with an automatically operated current or voltage magnitude
control means does not effect the wave propagation
characteristic of the filter are classified in subclasses
165+ below.
SEE OR SEARCH THIS CLASS, SUBCLASS:
2 for plural channel systems including automatic control.
13 for resonator type breakdown discharge systems which are
automatically controlled.
14 for amplitude compression and expansion systems including
automatic control.
15 for pilot line controlled systems involving automatic
operation.
16 for pilot current controlled systems including automatic
operation.
SEE OR SEARCH CLASS:
307, Electrical Transmission or Interconnection Systems,
appropriate subclasses, especially 92, 97, 99, and 116 for
miscellaneous electrical distribution systems with automatic
control means.
323, Electricity: Power Supply or Regulation Systems,
subclasses 234-303 for condition sensing regulators.
327, Miscellaneous Active Electrical Nonlinear Devices,
Circuits, and Systems, 509 and 518+ for miscellaneous
externally effected or control circuits.
331, Oscillators, 1 for oscillator systems utilizing a phase
or frequency sensing means for automatically stabilizing the
oscillator frequency subclass 183 for oscillator systems
having means for automatically controlling or stabilizing the
amplitude of the generated oscillations and subclass 186 for
oscillator systems with a particular source of power or bias
voltage of the automatically regulated type.
336, Inductor Devices, particularly 30 for inductor devices
automatically adjustable in response to a condition.
Subclass:
17.2
Limiting of Amplitude:
This subclass is indented under subclass 17.1. Subject
matter including means to limit the amplitude to a
predetermined level.
SEE OR SEARCH THIS CLASS, SUBCLASS:
81 for systems and networks that selectively lower the input
signal level to a desired amount.
SEE OR SEARCH CLASS:
307, Electrical Transmission or Interconnection Systems,
subclass 264 and 540+ for limiting the amplitude of pulses
in nonlinear solid state circuits.
Subclass:
17.3
Impedance Matching:
This subclass is indented under subclass 17.1. Subject
matter in which the condition sensed is utilized to control
circuitry that performs an impedance matching function in the
system.
SEE OR SEARCH THIS CLASS, SUBCLASS:
32 for impedance matching circuits of the nonautomatically
controlled type.
SEE OR SEARCH CLASS:
455, Telecommunications, 120 for frequency tuning a
transmitter to an antenna.
Subclass:
18
This subclass is indented under subclass 17. Systems and
networks provided with automatically operated means to
control an equalizer and delay network.
(1) Note. This subclass includes systems including an
equalizer and/or a delay network which is automatically
controlled in response to some condition in the system and
also equalizers and/or delay networks which are provided with
other automatic control means.
SEE OR SEARCH THIS CLASS, SUBCLASS:
12 for automatic equalization and/or delay control networks
utilized for preventing, suppressing or eliminating
interference.
15 for automatic equalization and/or delay control networks
controlled by the signal derived from a pilot line.
16 for automatic equalization and or delay control networks
involving a pilot current control.
28 for nonautomatic equalizers.
138 for nonautomatic delay networks.
SEE OR SEARCH CLASS:
323, Electricity: Power Supply or Regulation Systems,
subclasses 212-219 for automatic phase control systems
involving a single frequency.
363, Electric Power Conversion Systems, 2, 9+ and 36 for
plural conversion systems involving phase conversion;
subclasses 148+ for phase conversion systems, per se;
particularly subclass 149 for phase conversion systems
involving automatic voltage magnitude or phase angle
control.
Subclass:
19
This subclass is indented under the class definition.
Passive networks for producing an output wave which is the
time derivative or time integral of the input wave.
(1) Note. See the internal and external search notes under
subclass 20 of this class for wave shaping systems which may
involve differentiating and/or integrating networks.
SEE OR SEARCH THIS CLASS, SUBCLASS:
20 for passive networks for shaping the output wave to other
than the time derivative or time integral of the input wave.
Also see (1) Note above.
SEE OR SEARCH CLASS:
318, Electricity: Motive Power Systems, 609 and 611+,
particularly subclasses 621+ for position servomechanisms
which include stabilizing control features such as
integrating and differentiating networks; subclasses 141+ for
generator fed motor systems having generator control
including anti-hunt or rate of change response; subclass 702
for synchronous motor systems having anti-hunt or
anti-damping control; subclass 448, for open loop automatic
motor control systems involving anti-hunt control; and
subclasses 456+ for systems responsive to the rate of change
of a condition.
322, Electricity: Single Generator Systems, subclass 19 for
systems for automatically controlling the rate of change or
hunting of a generator or its driving means.
323, Electricity: Power Supply or Regulation Systems,
subclasses 212-219 for miscellaneous phase control networks
which involve differentiating or integrating networks.
327, Miscellaneous Active Electrical Nonlinear Devices,
Circuits, and Systems, subclass 335 for miscellaneous
differentiating circuits and subclasses 336+ for
miscellaneous integrating circuits.
708, Electrical Computers: Arithmetic Processing and
Calculating, subclass 822 and 823+ for calculators
performing computations involving differentiation and
integration, respectively.
Subclass:
20
This subclass is indented under the class definition.
Passive networks for modifying an electrical wave passing
therethrough so that the amplitude time characteristic of the
output wave is different from that of the input wave and
which have no function classified in other classes, and long
line wave transmission systems in combination with a passive
wave shaping network.
(1) Note. The networks are usually designed to modify or
shape a single pulse and usually involve a delay network or
equivalent delay means.
(2) Note. Included are long transmission lines in
combination with a wave shaping network which is designed to
restore the wave shape to a wave which has been distorted by
transmission over the transmission line.
(3) Note. Excluded are mere limiter networks which shape
the wave merely by cutting off the wave above a predetermined
amplitude.
(4) Note. Many systems and networks inherently function to
wave shape. Most of these systems are excluded as they
include active elements, such as oscillation generators,
amplifiers, detectors, etc. Where the network is primarily
designed for a purpose other than wave shaping, such as
controlling the magnitude of current in the circuit, the
network is excluded even though the control of the current
magnitude is effected by a means which also effects the wave
shape of the element.
SEE OR SEARCH THIS CLASS, SUBCLASS:
1 for systems combining wave energy from different channels
and/or separating wave energy into different channels.
14 for amplitude range compression and expansion systems.
19 for wave shaping networks producing a time derivative or
time integral of the applied wave energy (i.e.
differentiating or integrating networks).
28 for networks modifying the attenuation or attenuation and
phase characteristic with respect to frequency of the energy
passing therethrough (i.e. equalizers).
81 for attenuator networks.
SEE OR SEARCH CLASS:
84, Music, 622, 626+, 659+, 671 - 677 and 692 - 711 for
systems for the electrical production of complex waves in
musical instruments.
178, Telegraphy, 2, and particularly subclasses 63, 69 and
69.1 for telegraph systems involving combining and/or
separating and/or shaping of electric waves.
307, Electrical Transmission or Interconnection Systems, 106
for waveform or wave shape determinative or pulse producing
systems which are class appropriate. The networks and
systems in Class 307 may involve long line elements, but
ordinarily include also a specific source of wave energy or
pulse producing means, such as a DC source and switching
means.
324, Electricity: Measuring and Testing, 76.12 for
electrical systems for the analysis of complex waves, and
subclasses 76.39+ for electrical frequency measuring systems
which involve wave analysis.
327, Miscellaneous Active Electrical Nonlinear Devices,
Circuits, and Systems, 100 for miscellaneous converting,
shaping, or generating circuits such as miscellaneous
limiters and clock or pulse production circuits.
330, Amplifiers, 53 for amplifier systems combined with a
long line element, where the amplifiers may correct for the
distortions caused by the long line.
331, Oscillators, 75 for oscillator systems combined with an
output circuit including a space discharge or unilaterally
conductive device, which device may provide a wave distorting
or shaping function.
332, Modulators appropriate subclasses for modulator systems
which involve wave shaping.
340, Communications: Electrical, 825.77 for selective
electrical communication systems wherein the selective means
is responsive to the amplitude of the signal.
363, Electric Power Conversion Systems, appropriate
subclasses for conversion systems which involve wave shaping,
see 34 for systems for converting A.C. to D.C. and then
connecting the D.C. to A.C., subclasses 39+ for conversion
systems with means to introduce or eliminate frequency
components, and subclasses 157+ for frequency conversion
systems. The systems in Class 363 usually involve the use of
alternating current which is repetitive and do not involve
the shaping of a single pulse.
379, Telephonic Communications, appropriate subclasses for
telephone systems involving combining and/or separating
and/or shaping of electric waves.
Subclass:
21
This subclass is indented under the class definition. Wave
transmission systems comprising means for changing guided
waves having one field configuration to a different field
configuration, the original and changed waves each having a
longitudinal electric or magnetic field component.
(1) Note. This subclass includes means for changing a
rectangular TE wave pattern to a circular TE wave pattern,
e.g. for changing a plane polarized guided wave to a
circularly polarized guided wave, or from one type of
polarized wave to another.
SEE OR SEARCH THIS CLASS, SUBCLASS:
248 for mode filters or suppressors, and for wave guide
junctions (e.g. rotary joints involving mode conversion and
reconversion).
SEE OR SEARCH CLASS:
343, Communications: Radio Wave, subclass 756 for antennas
with a polarization converter; and subclasses 909+ for radio
wave polarizers, per se.
Subclass:
22
This subclass is indented under the class definition.
Networks specialized for use with and designed for connection
to the end of a long line transmission line and including a
resistive component for dissipating the wave energy
propagated along the line and presenting an essentially
resistive impedance to the line, and the combination of long
transmission lines with energy dissipating terminations.
(1) Note. Usually the impedance presented by the network is
equal to the characteristic impedance of the line for which
it is designed.
(2) Note. The termination classified here is usually more
than a mere resistance element such as is classified in Class
338, Electrical Resistors. The termination includes some
structure, such as a long line element or component, so that
the device is not of general utility, but is limited to use
with a transmission line. Long lines with mere resistance
elements which would, per se, be classified in Class 338, are
included in this subclass (22) when the resistance element is
designed for use as a long line dissipating termination.
SEE OR SEARCH THIS CLASS, SUBCLASS:
23 for networks simulating transmission lines (i.e.
artificial lines) whose function is not essentially
dissipating terminal energy.
32 for impedance matching networks whose function is
coupling as opposed to termination.
81 for attenuators, which dissipate only a portion of the
wave energy applied thereto.
SEE OR SEARCH CLASS:
343, Communications: Radio Wave, subclass 18 for radio wave
absorption devices; subclasses 731+ for traveling wave type
antennas which may involve a dissipating termination; and
subclasses 739+ for antennas with a terminating resistance at
open end.
361, Electricity: Electrical Systems and Devices, 117 for
surge dissipators and lightning arresters.
Subclass:
23
This subclass is indented under the class definition.
Networks for simulating impedance characteristics of a smooth
or loaded electrically long transmission line over a
frequency range.
SEE OR SEARCH THIS CLASS, SUBCLASS:
22 for dissipating terminations for long lines which usually
have an impedance characteristic equal to the characteristic
impedance of the line.
28 for equalizing networks having impedance characteristics
usually the inverse of electrically long transmission lines.
81 for attenuators.
SEE OR SEARCH CLASS:
330, Amplifiers, subclass 57, for amplifiers utilizing
artificial lines. (This also includes the "distributed
amplifiers").
Subclass:
24
This subclass is indented under the class definition. (1)
Networks including significant reactive structure for
effecting the transfer of oscillator energy from one circuit
to another circuit and having attenuation and/or delay
characteristics over a frequency range for attenuating and/or
delaying in a predetermined manner, wave energy passing
therethrough, and/or providing an impedance match between the
network and at least one of the circuits; (2) smoothing type
wave filters having shunt capacitance, or series inductance,
or both usually designed to pass direct current and to reduce
the effect of any undesired alternating or pulsating current,
or to pass direct current and low frequency alternating
current or pulsating current and to reduce the effect of any
undesired higher frequency alternating or pulsating current,
and (3) systems within the class definition including one or
more of the networks defined in (1) or (2) above.
(1) Note. The coupling networks under the above definition
usually include a shunt impedance common to the input and
output circuits.
(2) Note. The systems included are single channel systems
having coupling networks, and include for example echo
suppression on a single channel where the echo would be due
to an impedance mismatch, or the elimination of echo in a
single channel system by using a delay line. Such systems
are classified in the first indented subclass which provides
for the network used in the system. See section I,
subsection C, of the Class Definition.
(3) Note. Class 323, Electricity: Power Supply or
Regulation Systems, is the miscellaneous class for systems
for coupling a single source to a single load circuit using
only transformers and/or impedances. Also, see (4) Note
below.
(4) Note. Coupling networks using an electronic tube as a
part of the network are not included in this or the indented
subclass, but are classified in the appropriate class
providing for the system. For examples, see the Search Class
notes below.
(5) Note. See the Search Class notes below for a reference
to the classification lines between coupling networks and
antennas combined with such coupling networks.
SEE OR SEARCH THIS CLASS, SUBCLASS:
1 for plural channel systems involving coupling networks.
17 for automatically controlled systems involving coupling
networks.
81 for attenuators of the resistive type.
245 for transmission line joints within the class definition
which do not modify the characteristics of the wave
propagated therethrough or do not effect an impedance match
between dissimilar impedance lines or networks.
SEE OR SEARCH CLASS:
178, Telegraphy, appropriate subclasses for coupling networks
in combination with code signaling systems or apparatus other
than telephony. See subclass 64 for such systems for
transmitting messages by induced currents utilizing an
induction coil or transformer, and for such systems having an
induction coil or transformer between sections of the main
line.
307, Electrical Transmission or Interconnection Systems,
particularly 1 for miscellaneous superimposed current
systems involving coupling networks, and subclasses 11+ and
43+ for miscellaneous plural load or plural supply systems
which include coupling networks.
323, Electricity: Power Supply or Regulation Systems. See
(3) Note, above. Class 323 provides for the miscellaneous
transformer and impedance systems and includes structural
combinations of different impedances which are electrically
connected together.
323, Electricity: Power Supply or Regulation Systems, for a
coupling network using tubes to control the current and/or
voltage magnitude and/or for phase control where there is a
single input and output and at least a part of the input
energy appears in the output circuit. (See the (4) Note
above)
327, Miscellaneous Active Electrical Nonlinear Devices, 261
for a delay system using tubes; subclasses 552+ for a filter
using tubes; subclass 231 for a phase shifter using tubes
where the input energy is applied to an input electrode
(e.g., grid) of the tube to control a local source of energy
(e.g., anode supply) connected to the output electrode of the
tube (See the (4) Note above)
330, Amplifiers, appropriate subclasses for various types of
coupling networks involved in amplifier systems, subclass 116
for an amplifier system with means to couple a balanced line
to an unbalanced line. (See the (4) Note above)
331, Oscillators, 74 for oscillation generators combined
with a particular output coupling network.
334, Tuners, for tuners, per se. See also (4) Note above for
tuners combined with other systems.
336, Inductor Devices, appropriate subclasses for the
structure of transformers and inductances of the passive
type.
343, Communications: Radio Wave, subclass 743 for high
frequency loop type antennas with feed coupling at spaced
points on the loop; subclass 771 for slot type antennas with
wave guide coupling; subclasses 814, 816 and 820+ for
balanced doublet type antennas with a coupling network,
subclasses 850+ for antennas in general with a coupling
network or impedance in the leadin; subclass 700, (11) Note,
for the classification lines between coupling networks and
antennas combined with such coupling networks (see the (5)
Note above).
361, Electricity: Electrical Systems and Devices, 600 for
miscellaneous combinations of different impedances which are
not in circuit relationship (e.g., a variable condenser
combined with a resistance with no electrical connection
between them).
379, Telephonic Communications, appropriate subclasses for
telephone systems having coupling networks. If the system is
limited to use with speech (other than by mere name), such as
including a microphone or reproducer (e.g., loudspeaker) the
system is classified in Class 381, see 338 for repeaters
utilizing hybrid coil systems.
455, Telecommunications, 91 for radio transmitters involving
coupling networks and subclasses 130+ (particularly
subclasses 338+) for radio receivers involving coupling
networks.
Subclass:
24.1
This subclass is indented under subclass 24. Networks which
include gyromagnetic elements for effecting a nonreciprocal
transfer of oscillatory energy from one circuit to another
circuit.
(1) Note. See (1) Note under subclass 1.1 above for a
definition of the terms "gyromagnetic" and "nonreciprocal".
Many of the patents in this generic subclass 24.1 are
directional phase shifters, and relate to networks that shift
the phase of energy passing through by different amounts
depending on the direction of passage.
SEE OR SEARCH THIS CLASS, SUBCLASS:
1.1 for plural channel nonreciprocal gyromagnetic systems.
See also (1) Note above.
138 for delay networks generally.
202 for waveguide filters generally.
SEE OR SEARCH CLASS:
324, Electricity: Measuring and Testing, 300 for nuclear or
electronic induction measuring or testing devices.
330, Amplifiers, subclass 4, 4.8 and 63 for amplifiers using
gyromagnetic elements.
455, Telecommunications, subclass 323 for mixers using
gyromagnetic elements.
Subclass:
24.2
This subclass is indented under subclass 24.1. Networks
wherein the attenuation in one direction of propagation
through the network is substantially greater than in the
opposite direction.
(1) Note. The attenuation in one direction may be
substantially zero.
SEE OR SEARCH THIS CLASS, SUBCLASS:
81 for attenuators generally.
Subclass:
24.3
This subclass is indented under subclass 24.1. Networks
wherein the polarization of the electric vector of the wave
energy propagated through the network is rotated in the same
absolute sense for both directions of propagation.
(1) Note. Included in this subclass are the so-called
anti-reciprocal or Faraday rotators.
SEE OR SEARCH THIS CLASS, SUBCLASS:
248 for rotators generally.
Subclass:
25
This subclass is indented under subclass 24. Networks
including four terminals, the impedance across one pair of
terminals being symmetrical and the impedance across another
pair of these terminals being unsymmetrical with respect to a
given potential plane (e.g., ground), these impedances being
effective to convert symmetrical potential applied at the
symmetrical pair of terminals to unsymmetrical potential at
the other pair of terminals or to convert unsymmetrical
potential applied at the unsymmetrical pair of terminals to
symmetrical potential at the other pair of terminals, and
systems under the class definition including a balanced to
unbalanced circuit coupling.
SEE OR SEARCH THIS CLASS, SUBCLASS:
1 for plural channel systems, which involve coupling a
balanced circuit to an unbalanced circuit or vice versa.
12 for systems for reducing inductive or radiation
interference and which include coupling between balanced and
unbalanced circuits.
SEE OR SEARCH CLASS:
323, Electricity: Power Supply or Regulation Systems,
subclasses 212-219 for phase control systems with means to
introduce delay into a part of the system, and including such
systems using reactive impedances and transformer systems to
obtain a phase shift (e.g., a 1805 shift) and which are
designed for use at a single frequency.
329, Demodulators, appropriate subclasses for demodulators
having inputs or outputs which are balanced or unbalanced.
330, Amplifiers, subclass 275 and 301 for transistor
amplifiers with balanced-to-unbalanced coupling and vice
versa, subclass 116 for amplifier systems having
balanced-to-balanced coupling, and subclass 117 for amplifier
systems having unbalanced-to-balanced coupling.
343, Communications: Radio Wave, subclass 821 for balanced
doublet type antennas with a balanced to unbalanced coupling
network; and subclass 859 for antennas in general with a
balanced to unbalanced coupling network.
363, Electric Power Conversion Systems, 2, 9+, 36, and 148+
for systems converting energy from one number of phases to a
different number of phases.
Subclass:
26
This subclass is indented under subclass 25. Balanced to
unbalanced circuit coupling networks and systems where the
coupling network includes a long line element.
SEE OR SEARCH THIS CLASS, SUBCLASS:
236 for long lines.
245 for long line elements.
Subclass:
27
This subclass is indented under subclass 24. Coupling
systems having a long line with a coupling network at each
opposed ends of the long line.
(1) Note. Where the long line is merely a part of a
coupling network, and does not link two different coupling
networks together, classification is not in this subclass.
See subclasses 156+ for this type of delay network,
subclasses 50+ for this type of impedance matching network,
202+ for this type of wave filter.
(2) Note. In this subclass are systems having two coupling
networks with a long transmission line connected to transmit
energy from one network to the other. These systems approach
a complete system. For example, a 70 ohm source connected by
a network to a 300 ohm line which is coupled by a network to
a 150 ohm receiver. At each point of connection there would
be a coupling network.
SEE OR SEARCH THIS CLASS, SUBCLASS:
50 see (1) Note above.
156 see (1) Note above.
202 see (1) Note above.
236 for long lines, per se.
SEE OR SEARCH CLASS:
178, Telegraphy, appropriate subclasses where the system is
limited to code signaling other than telephony.
330, Amplifiers, 53 for amplifier systems combined with long
lines or long line elements wherein such means furnish a
coupling means for the amplifier.
379, Telephonic Communications, 90 for composite telephone
systems (e.g., combined power and telephone circuit) and
subclasses 338+ for two telephone lines with two-way
repeaters at spaced points along the line.
381, Electrical Audio Signal Processing Systems and Devices,
82 for public address and similar systems (e.g., a
microphone and a line, or a line and a reproducer such as a
loudspeaker or a microphone, a line and a reproducer).
Subclass:
28
This subclass is indented under subclass 24. Networks with
attenuation or attenuation and phase distortion
characteristics which vary over a frequency range for use in
a wave transmission system for modifying the attenuation or
attenuation and phase characteristics of the wave energy as a
function of frequency, and systems within the class
definition which include such networks.
(1) Note. Equalizer networks are used to reduce the
attenuation or attenuation and phase distortion
characteristics which the wave energy in a long line
transmission system would have in the absence of the network.
The network may be used for predistorting so that the
distorting effect of the long line will be corrected.
(2) Note. A filter is distinguished from an equalizer in
that a filter is intended and designed to transmit a
frequency or one or more bands of frequencies without
modification while undesired frequencies are attenuated to a
low value so that the desired frequency or frequencies are
transmitted by the filter and the undesired frequencies are
substantially blocked, while the equalizer has the function
of changing the relative amplitudes of the waves of different
frequency over the range of frequencies transmitted by the
equalizer.
(3) Note. Included are tone control networks which involve
only passive elements and which vary the attenuation or
attenuation and phase distortion characteristics over a range
of frequencies. Included are such networks as are used for
"bass boosters", "treble boosters", "treble cut systems",
etc.
SEE OR SEARCH THIS CLASS, SUBCLASS:
18 for this subject matter where the equalizer is provided
with automatic control means.
20 for wave shaping systems.
81 for attenuator networks within the class definition
composed entirely of resistive elements.
138 for phase control or delay networks, per se.
SEE OR SEARCH CLASS:
323, Electricity: Power Supply or Regulation Systems,
appropriate subclasses for miscellaneous impedance and
transformer systems, and for phase control systems.
330, Amplifiers, appropriate subclasses, particularly
subclass 109, 120, 122, 154, 157+, 185+, 192+, and 304, for
amplifier systems combined with an equalizer network.
332, Modulators, subclass 107 for distortion control in
pulse modulators, subclasses 123+ for distortion control in
frequency modulators, subclasses 144+ for distortion control
in phase modulators, and subclasses 159+ for distortion
control in amplitude modulators.
381, Electrical Audio Signal Processing Systems and Devices,
98 for audio signal processing devices and systems having
frequency control.
455, Telecommunications, subclass 267 for radio receivers
with tone control networks.
Subclass:
32
This subclass is indented under subclass 24. Coupling
networks which include one or more impedance elements
constructed or proportioned to substantially eliminate the
reflected wave energy between the network and at least one of
the connected circuits caused by impedance differences;
impedance matching networks, per se; and systems within the
class definition which include such networks.
(1) Note. The particular construction or proportioning
producing the impedance match should be claimed for
classification in this subclass.
(2) Note. The impedance need only to be matched to pass the
energy or frequency band of energy desired.
SEE OR SEARCH THIS CLASS, SUBCLASS:
8 for branched plural channel systems having impedance
matching.
17 for systems wherein the impedance match is automatically
controlled.
22 for line terminations involving impedance matching.
81 for attenuators having means for compensating for changes
in terminal impedance caused by adjustment of the attenuator
so as to match the impedances of the attenuator to the
connected input and/or output circuit.
236 for long lines wherein reflected wave energy arising
from the line structure is compensated.
SEE OR SEARCH CLASS:
324, Electricity: Measuring and Testing 600, especially
subclasses 612+ for the miscellaneous measurement and testing
of impedance mismatch between circuits, and subclass 140+,
for systems and apparatus for the measurement of voltage,
current or power ratios which are indicative of impedance
mismatch.
343, Communications: Radio Wave, subclass 822 for balanced
doublet type antennas with an impedance matching coupling
network; and subclasses 860+ for antennas in general with an
impedance matching coupling network.
Subclass:
33
This subclass is indented under subclass 32. Impedance
matching networks and systems including a long line element.
SEE OR SEARCH THIS CLASS, SUBCLASS:
236 for long lines.
245 for long line elements.
SEE OR SEARCH CLASS:
343, Communications: Radio Wave, subclass 862 for antennas
with an impedance matching coupling network including a long
line element.
Subclass:
34
This subclass is indented under subclass 33. Impedance
matching networks and systems wherein the long line element
lies along the path of wave propagation through the network
and has a physical dimension progressively increasing or
decreasing along the path of propagation to result in a
corresponding change in electrical parameters of the long
line element.
SEE OR SEARCH CLASS:
343, Communications: Radio Wave, subclass 863 for antennas
with an impedance matching coupling network including a
tapered long line element.
Subclass:
35
This subclass is indented under subclass 33. Impedance
matching networks and systems wherein the component having
distributed electrical parameters lies along the path of wave
propagation through the network and is an odd integral number
of quarter-wave lengths long.
SEE OR SEARCH CLASS:
343, Communications: Radio Wave, subclass 864 for antennas
with an impedance matching coupling network including a long
line element of the quarter-wave transformer type.
Subclass:
81
This subclass is indented under the class definition.
Devices and networks consisting of one or more elements which
exhibit only a positive resistance effect and which reduce
the intensity of the energy passing through the device by
dissipation, (1) the elements being proportioned to permit a
change in their value to control the energy loss while
maintaining substantially constant input and/or output
impedance of the device, and/or (2) the elements being
proportioned to permit the device to be inserted in the
circuit to provide an energy loss without introducing any
reflections in the circuit, and/or (3) the elements being
combined with a long line or long line element, and/or (4)
the device or network having an impedance equal to the
impedance of a specified long line and/or (5) the device or
network is claimed as being particularly modified for use
over a frequency band so that its characteristics are
particularly related to frequency, and (6) systems within the
class definition including such devices or networks.
(1) Note. The networks and devices of part 5 of the
definitions may include means such as capacitors to
compensate for deviations in attenuation caused by changes in
frequency of the applied energy, so that the device or
network acts as a pure resistance. The network or device may
be modified to obtain uniform attenuation over a band of
frequencies.
(2) Note. Included are T, H, pad, and ladder or lattice
type networks as well as transmission line sections.
(3) Note. This subclass embraces devices wherein one or
more of the elements include reactance to compensate for any
inherent reactance of the element or elements, see (1) Note.
(4) Note. If the device or network does not maintain a
constant input and/or output impedance, or if it would
introduce reflections into the transmission line, it is
excluded from this class and will be found in Class 323
Electricity: Power Supply or Regulation Systems.
SEE OR SEARCH THIS CLASS, SUBCLASS:
13 for resonator type breakdown discharge systems, which
include attenuation networks.
14 for amplitude compression and expansion systems which
include attenuation networks.
15 and 16, for pilot controlled systems which include
attenuation networks.
17 for automatically controlled systems which may include
attenuation networks.
22 for transmission line terminations which dissipate the
applied energy.
24 for adjustable reactive type coupling networks in
general, see especially subclass 28 for equalizer networks.
SEE OR SEARCH CLASS:
181, Acoustics, appropriate subclasses, for devices for
attenuating sound, see subclass 206 for mufflers.
323, Electricity: Power Supply or Regulation Systems, see
(4) Note above.
330, Amplifiers, appropriate subclasses under 157+, 185+ and
192+ for amplifiers having significant coupling which may
include attenuators.
338, Electrical Resistors, appropriate subclasses, for
electrical resistors, per se; and 68 for mechanically
variable resistors including potentiometers and rheostats.
Subclass:
99
This subclass is indented under the class definition.
Subject matter which is not provided for in any of the
preceding subclasses in this class.
Subclass:
100
Having branched circuits:
This subclass is indented under subclass 1. Systems
including means for effecting an interchange of wave energy
from one transmission line to two or more transmission lines,
or vice versa, or having a coupling network for effecting an
interchange of wave energy from a single input to plural
outputs, or vice versa, of energy together with means for
controlling or facilitating this interchange of energy.
SEE OR SEARCH THIS CLASS, SUBCLASS:
2 for plural channel branched circuit systems having
automatic controlled means to control the system.
4 for plural channel systems and coupling networks wherein
at least one of the transmission lines is a balanced line or
where the network is especially designed for coupling to at
least one balanced line.
13 for resonator type breakdown discharge circuits which
include a space discharge device designed to breakdown in
response to high level energy (e.g., from the transmitting
section of the system) to block substantially the flow of
high level energy, and to pass low level energy along the
transmission line (e.g., to a receiver). The devices in
subclass 13 include T-R and R-T systems.
SEE OR SEARCH CLASS:
174, Electricity: Conductors and Insulators, particularly
subclass 38, 43, 49, and 71+ for branched electrical
conductor structures other than loaded lines and conductors
defined as having long line characteristics.
307, Electrical Transmission or Interconnection Systems,
particularly 11, 43+, and 147+ for miscellaneous electrical
distribution systems which include branched circuits.
327, Miscellaneous Active Electrical Nonlinear Devices,
Circuits, and Systems, 407 for miscellaneous circuits for
use in coupling plural channels to a single channel.
331, Oscillators, 60 for an electrical oscillation generator
provided with plural output circuits.
343, Communications: Radio Wave Antennas, subclass 771 for
plural slot-type antennas with wave guide coupling;
subclasses 776+ for plural waveguide type antennas with
coupling; subclasses 814 and 816 for plural balanced doublet
type antennas with a coupling network; subclasses 853+ for
plural antennas generally with a coupling network; subclass
858 for antennas coupled to plural lead-ins.
375, Pulse or Digital Communications, 268, 353 for duplex
systems having an antenna coupling network coupling a
transmitter and a receiver to an antenna.
439, Electrical Connectors, 150 and 242 for multiple
connector structure; subclasses 241+ for line tapper
connector structure such as alligator clips and test probes.
455, Telecommunications, 132 for antenna coupling networks
for plural receivers where the coupling network includes an
active element and/or significant receiver structure; and
subclasses 103+ for similar subject matter for transmitters.
Subclass:
101
Including switching means:
This subclass is indented under subclass 100. Systems with
means for abruptly connecting and disconnecting two or more
transmission lines to or from another transmission line.
(1) Note. The systems in this subclass usually having means
to reduce reflected waves resulting from impedance
discontinuities or irregularities caused by the presence or
operation of the connecting and disconnecting means.
(2) Note. Plural circuit switches restricted to use in a
particular art are sometimes classified with the art, for
example, switches in telegraph systems and switches in
telephone systems are classified elsewhere.
(3) Note. Variable power dividers which are classified
below normally have a continuously variable transfer of power
which is not abrupt.
SEE OR SEARCH THIS CLASS, SUBCLASS:
2 for similar systems having automatically controlled
means.
3 for automatically controlled line substitution systems.
13 for single channel resonator type break-down discharge
systems where the resonator-discharge device is used to
effectively short circuit or open circuit the line (e.g., R-T
or T-R systems).
258 and 262, for transmission line elements for single
channels which may be used to perform a switching or blocking
function.
SEE OR SEARCH CLASS:
178, Telegraphy, for switches in telegraph systems
200, Electricity: Circuit Makers and Breakers, particularly
1 and 19.01+ for plural circuit switches of general utility
and not limited by claimed structure to use with long lines.
307, Electrical Transmission or Interconnection Systems,
particularly subclass 23, 38+, 64+, 80+, 85+, 98+, and 112+
for miscellaneous electrical distribution systems which
include switching.
331, Oscillators, subclass 49 for plural oscillator systems
provided with means for selectively connecting one or more of
two or more oscillators to a common output circuit.
379, Telephonic Communications, for switches in telephone
systems, especially 242.
Subclass:
102
Having gyromagnetic operating means:
This subclass is indented under subclass 101. Subject matter
whereby a gyromagnetic element, e.g., fettile, is used as the
switching element.
Subclass:
103
Having semiconductor operating means:
This subclass is indented under subclass 101. Subject matter
whereby the switching means is a semiconductive element
(e.g., diode).
Subclass:
104
Using TEM lines:
This subclass is indented under subclass 103. Subject matter
whereby the dominant mode in the transmission lines is of the
type having only transverse electromagnetic components.
(1) Note. Examples of such lines are coaxial lines,
striplines, and microstrip lines.
Subclass:
105
Having mechanical switching means:
This subclass is indented under subclass 101. Systems
wherein the means for abruptly connecting and disconnecting
two or more transmission lines to or from another
transmission line is a mechanical element.
(1) Note. The systems in this subclass usually have means
to reduce reflected waves resulting from impedance
discontinuities or irregularities caused by the presence or
operation of the connecting and disconnecting means.
(2) Note. Plural circuit switches restricted to use in a
particular art are sometimes classified with the art, for
example, switches in telegraph systems are classified in
Class 178, Telegraphy, and switches in telephone systems are
classified in Class 379, Telephonic Communications, see
especially subclasses 242+.
(3) Note. Variable power dividers normally have a
continuously variable transfer of power which is not abrupt.
(4) Note. Examples of the types of mechanical elements used
are movable shorting pins, rotating assemblies, and movable
transmission lines.
SEE OR SEARCH THIS CLASS, SUBCLASS:
2 for similar systems having automatically controlled
means.
3 for automatically controlled line substitution systems.
13 for single channel resonator type breakdown discharge
systems, where the resonator discharge device is used to
effectively short circuit or open circuit the line (e.g., R-T
or T-R systems).
262 for connection and disconnection of long lines.
SEE OR SEARCH CLASS:
200, Electricity: Circuit Makers and Breakers, particularly
1 and 19.01+ for plural circuit switches of general utility
and not limited by claimed structure to use with long lines.
307, Electrical Transmission or Interconnection Systems,
particularly subclass 23, 38+, 64+, 80+, 85+, 98+, and 112+
for miscellaneous electrical distribution systems which
include switching.
331, Oscillators, subclass 49 for plural oscillator systems
provided with means for selectively connecting one or more of
two or more oscillators to a common output circuit.
Subclass:
106
Using rotary switching means:
This subclass is indented under subclass 105. Subject matter
wherein the mechanical element rotates about an axis through
the switch device.
Subclass:
107
For TEM lines:
This subclass is indented under subclass 106. Subject matter
whereby the dominant mode in the transmission lines is of the
type having only transverse electromagnetic components.
Subclass:
108
For waveguide:
This subclass is indented under subclass 105. Subject matter
whereby the transmission device propagates electrical waves
having and electric or magnetic field component extending in
the direction of propagation.
Subclass:
109
Using directional coupler:
This subclass is indented under subclass 100. Wave
transmission systems including two transmission lines having
an intervening coupling which propagates a portion of the
energy passing in one direction along the first line in the
second line in only one direction from the coupling, and
which propagates a portion of the energy which may pass in
the other direction along the first line in the second line
in the opposite direction only from the coupling.
(1) Note. The second line may include a means, such as a
dissipative termination, so that the energy from one
direction only will be propagated to a distance in the second
line. For example,
[figure] [figure]
SEE OR SEARCH THIS CLASS, SUBCLASS:
117 for a plurality of lines connected to a line by means of
a hybrid coil.
Subclass:
110
For providing frequency separation:
This subclass is indented under subclass 109. Subject matter
wherein the interchange of energy results in the separation
or combination of a plurality of frequencies or frequency
bands.
Subclass:
111
For providing adjustable coupling:
This subclass is indented under subclass 109. Subject matter
wherein the amount of electromagnetic energy transferred
between the first and second transmission lines can be
changed to provided a different coupling ratio.
Subclass:
112
Having lumped parameters or impedances:
This subclass is indented under subclass 109. Subject matter
wherein an impedance element is included which may be
considered as concentrated at one point.
(1) Note. See the class definition for the definition of
"lumped parameters" or impedances.
Subclass:
113
Having parallel-guide waveguide:
This subclass is indented under subclass 109. Subject matter
wherein the first and second transmission lines are
waveguides; the direction of energy propagation in the first
and second lines being parallel in the coupling region.
Subclass:
114
Having crossed-guide waveguide:
This subclass is indented under subclass 109. Subject matter
wherein the first and second transmission lines are
waveguides; the direction of propagation in the first and
second lines being transverse to each other in the coupling
region.
Subclass:
115
Having TEM lines:
This subclass is indented under subclass 109. Subject matter
wherein the first and second transmission lines are the type
having only transverse electromagnetic components and no
longitudinal electromagnetic components as their primary mode
of operation.
Subclass:
116
Using stripline:
This subclass is indented under subclass 115. Subject matter
wherein each of the first and second transmission lines have
a planar center conductor and a planar ground plate.
Subclass:
117
Including hybrid-type network:
This subclass is indented under subclass 100. Systems
including coupling one wave transmission line to two or more
wave transmission lines in such manner that there is a
conjugate relation between at least two of these coupled
transmission lines to prevent any interchange of energy
between the conjugately related lines.
SEE OR SEARCH THIS CLASS, SUBCLASS:
22 for transmission line terminations for hybrid-type
networks.
23 for artificial lines adapted for use in hybrid systems.
24 for single channel coupling networks. 109, for branched
circuits including a directional coupler so that wave energy
passing in one direction along a first line will be
propagated in the second line in only one direction from the
coupling, and wave energy passing in the other direction
along the first line will be propagated only in the opposite
direction from the coupling.
169 and 170+, for bridge-type filter networks.
SEE OR SEARCH CLASS:
323, Electricity: Power Supply or Regulation Systems,
subclass 365 for bridge-type impedance systems.
336, Inductor Devices, appropriate subclasses for the
structure of transformers per se.
370, Multiplex Communications, appropriate subclasses,
particularly 276 for a duplex system, subclass 308 for a
resonant transfer system, and subclasses 498+ for combining
or distributing information via time channels which may
include a hybrid circuit.
379, Telephonic Communications, 338 for repeater systems
including hybrid-type networks; and subclasses 402+ for
telephone substation circuits including hybrid-type
networks.
455, Telecommunications, 7 for radio repeaters including
hybrid networks.
Subclass:
118
Having lumped parameters or impedances:
This subclass is indented under subclass 117. Subject matter
having impedance elements which may be considered as
concentrated at one point.
Subclass:
119
Using transformer coil:
This subclass is indented under subclass 118. Subject matter
wherein the impedance element consists of mutually coupled
windings.
Subclass:
120
Having hybrid ring junction:
This subclass is indented under subclass 117. Subject matter
wherein the hybrid transmission line forms a closed loop,
there being a plurality of ports connected to the loop.
Subclass:
121
Having hybrid-T (e.g., magic-T):
This subclass is indented under subclass 117. Subject matter
wherein the hybrid has four ports; energy being interchanged
between the first port and two other ports, with no energy
propagation from the fourth port, and the first and fourth
ports being decoupled.
Subclass:
122
Using waveguide:
This subclass is indented under subclass 121. Subject matter
wherein the transmission line is of the type having an
electric or magnetic field extending in the direction of
propagation.
Subclass:
123
Having coaxial element:
This subclass is indented under subclass 117. Subject matter
wherein the transmission is of the TEM type having an
elongated center conductor and a surrounding outer
conductor.
Subclass:
124
With impedance matching:
This subclass is indented under subclass 100. Systems
wherein the interconnected or branched transmission lines
present impedances at their junction to substantially
eliminate the reflected wave energy caused by the junction or
wherein one or more impedance elements are provided which are
constructed or proportioned to substantially eliminate the
reflected wave energy caused by the branched circuit coupling
means.
SEE OR SEARCH THIS CLASS, SUBCLASS:
2 for branched circuit impedance matching which is
automatically controlled.
22 for single channel transmission line terminations
involving impedance matching.
32 for single channel impedance matching coupling networks.
SEE OR SEARCH CLASS:
324, Electricity: Measuring and Testing, 600 especially
subclasses 612+ for the miscellaneous measurement and testing
of impedance mismatch between circuits; and subclasses 140+
for systems and apparatus for the measurement of voltage,
current, or power ratios which are indicative of impedance
mismatch.
343, Communications: Radio Wave Antennas, subclass 852 for
antennas with a plural path coupling network with impedance
matching.
Subclass:
125
Including long line element:
This subclass is indented under subclass 124. Subject matter
wherein a circuit element having distributed parameters is
used.
Subclass:
126
For providing frequency separation:
This subclass is indented under subclass 125. Subject matter
wherein the impedance matched branching network provides a
different frequency or band of frequencies in each of the two
or more transmission lines or in the plural outputs.
Subclass:
127
Using TEM lines:
This subclass is indented under subclass 125. Subject matter
wherein the transmission lines are the type having only
transverse electromagnetic components as their primary mode
of operation.
Subclass:
128
Stripline:
This subclass is indented under subclass 127. Subject matter
wherein the TEM lines are of the type having a planar center
conductor and a planar ground plate.
Subclass:
129
For providing frequency separation:
This subclass is indented under subclass 124. Subject matter
wherein the branched transmission lines provide a different
frequency or band of frequencies in each of the two or more
transmission lines.
Subclass:
130
Using resistors only:
This subclass is indented under subclass 124. Subject matter
wherein the impedance matching elements consist solely of
resistors.
Subclass:
131
Using coupled windings:
This subclass is indented under subclass 124. Subject matter
wherein the impedance matching elements comprise inductively
coupled coils (i.e., transformers and auto transformers).
Subclass:
132
For providing frequency separation:
This subclass is indented under subclass 100. Subject matter
wherein the interchange of wave energy provides a different
frequency or band of frequencies in each of the two or more
transmission lines or in the plural outputs.
Subclass:
133
Utilizing electromechanical transducer:
This subclass is indented under subclass 132. Subject matter
wherein an electrical wave driven mechanical vibrator
determines the frequency characteristic of the branched
circuit.
Subclass:
134
Utilizing long line element:
This subclass is indented under subclass 132. Subject matter
wherein the transmission lines or coupling networks include
an element having distributed parameters.
(1) Note. LONG LINE ELEMENT: A circuit element having
distributed parameters, such as a resonator, or a waveguide.
A long line element may be a part of a long line wave
transmission device or used in a network with other circuit
elements of the lumped parameter type, for example, as in the
case of delay networks, impedance matching networks, and wave
filters.
Subclass:
135
Including waveguide element:
This subclass is indented under subclass 134. Subject matter
wherein the long line element is of the type having a
magnetic or electrical component extending in the direction
of propagation.
(1) Note. WAVEGUIDE: A transmission device designed to
propagate electrical waves having an electric or magnetic
field component extending in the direction of propagation.
The waveguide may be a hollow dielectric or metal tube or a
solid dielectric rod, the wave energy being propagated along
the interior of the tube or rod and confined by the walls of
the tube or rod.
Subclass:
136
Including long line element:
This subclass is indented under subclass 100. Subject matter
wherein the branched circuit includes a circuit element
having distributed parameters.
Subclass:
137
Using waveguide:
This subclass is indented under subclass 136. Subject matter
wherein the long line element is of the waveguide type.
Subclass:
138
Delay lines including a lumped parameter:
This subclass is indented under subclass 24. Subject matter
for retarding wave energy a predetermined time over a range
of frequencies and systems within the class definition which
include such networks and wherein one of the network
parameters may be considered as concentrated at one point.
(1) Note. See the class definition for the definition of
"lumped parameters".
(2) Note. The time period may be constant over the range of
frequencies or proportional to the frequency (e.g., the time
of delay may be greater for the higher frequency).
(3) Note. This subclass does not contain pulse delay
systems utilizing active elements.
(4) Note. Devices for adjusting or maintaining the phase
angle between the current and the voltage of an electric wave
of a single frequency, or the phase angle between the current
or voltage of a single frequency with respect to a standard
or with respect to the current or voltage of another circuit
are classified in Class 323, Electricity: Power Supply or
Regulation Systems, subclasses 212-219 wherein there is a
single input source and a single output load and wherein the
phase shift is produced by the device acting on the original
electrical energy and not due to any interposed signal
controlled transducer. Class 307, Electrical Transmission or
Interconnection Systems, appropriate subclasses also provides
for the miscellaneous phase control systems similar to these
in Class 323 but having plural source circuits and/or plural
load circuits.
(5) Note. Class 363, Electric Power Conversion Systems,
subclasses 2, 9, 148, and indented subclasses provides for
systems for transforming electrical energy having one number
of phases to electrical energy having another number of
phases.
SEE OR SEARCH THIS CLASS, SUBCLASS:
18 for automatically controlled delay networks.
19 for differentiating or integrating systems involving
delay networks.
20 for wave synthesis and shaping systems involving delay
networks.
28 for combined attenuation and phase control networks, per
se.
SEE OR SEARCH CLASS:
178, Telegraphy, particularly subclass 17.5 for transmitter
for storing or delaying messages or code signals; subclasses
45+ for wave transmission lines with inductive loading means
to effect changes in the delay characteristics of the
transmission lines; subclass 63 for phase or delay control
means applied to high capacity transmission line systems; and
subclass 69 for line-clearing and circuit maintenance systems
which include distortion and phase correction means.
307, Electrical Transmission or Interconnection Systems, see
(4) Note above.
323, Electricity: Power Supply or Regulation Systems,
subclasses 212-219, see (4) Note above.
324, Electricity: Measuring and Testing, 76.77 for phase
indicators.
327, Miscellaneous Active Electrical Nonlinear Devices,
Circuits, and Systems, 261 for miscellaneous circuits which
may include an electron discharge device or transistor and
provide specific delay in producing an output waveform. see
(3) Note above.
330, Amplifiers, appropriate subclasses for amplifiers
combined with phase shifting networks and for phase inverter
systems involving active elements having an amplifier
function appropriate subclasses for phase compensation in
amplifier systems. Also see (3) Note above.
329, Demodulators, 315 for frequency demodulators and
subclasses 345+ for phase demodulators.
331, Oscillators, appropriate subclasses for oscillation
generators utilizing time delay networks, particularly
subclass 82 for beam tube oscillators of the traveling wave
type; and subclasses 135+ for phase shift oscillators,
indented subclass 137 providing for such oscillators with a
phase shift network of the RC ladder type.
332, Modulators, 144 for phase modulation systems.
336, Inductor Devices, appropriate subclasses for the
structure of inductive reactors.
343, Communications: Radio Wave Antennas, subclass 744 for
high frequency loop-type antennas with series reactance in
the loop; subclasses 749+ for antennas with lumped reactance
for loading the antenna; and subclass 778 for plural
waveguide-type antennas with phasing.
361, Electricity: Electrical Systems and Devices, 271 for
capacitor structure.
379, Telephonic Communications, subclass 398 and 415 for
phase modifying means applied to anti-inductive systems.
Subclass:
139
Variable parameter:
This subclass is indented under subclass 138. Subject matter
including at least one variable parameter for delay
adjustment.
Subclass:
140
Physical structure:
This subclass is indented under subclass 138. Delay lines
subject matter wherein the geometry of individual parameters
or the physical distribution of elements is critical to
obtaining the desired delay.
(1) Note. Included here would be inductive parameters
having a specific core structure and/or winding geometry.
Subclass:
141
Delay lines including elastic bulk wave propagation means:
This subclass is indented under subclass 24. Subject matter
for retarding wave energy a predetermined time over a range
of frequencies and systems within the class definition which
include such networks wherein structure is provided for
converting electrical wave energy to bulk wave mechanical
energy, and for transmitting the bulk wave mechanical energy
for reconversion to electrical wave energy.
(1) Note. The time period may be constant over the range of
frequencies or proportional to the frequency (e.g., the time
of delay may be greater for the higher frequency).
(2) Note. The delay is due to the lower propagation
velocity of waves in the mechanical wave transmission path.
(3) Note. Included as mechanical wave transmission devices
in this subclass are such devices as fluid columns, bars,
rods, and plates.
(4) Note. By elastic bulk wave propagation is meant energy
transmitted through the interior of an elastic wave
propagation medium.
SEE OR SEARCH THIS CLASS, SUBCLASS:
186 for electromechanical filters employing bulk mode
resonators.
SEE OR SEARCH CLASS:
74, Machine Element or Mechanism, appropriate subclasses,
especially subclass 1 for mechanical systems of linkages to
shift the phase of a wave.
310, Electrical Generator or Motor Structure, subclass 313
for piezoelectric surface acoustic wave devices; subclasses
334+ for various acoustic wave devices which use
piezoelectric effects; and subclass 26 for miscellaneous
magnetostrictive devices, per se.
318, Electricity: Motive Power Systems, subclass 116 for
piezoelectric motors; and subclass 118 for magnetostrictive
motors.
322, Electricity: Single Generator Systems, subclass 3 for
magnetostrictive generator systems.
343, Communications: Radio Wave Antennas, 5 for radar and
other reflected wave radio systems used to measure distance
and which use delay networks, see especially subclasses 9,
10+, and 12+.
367, Communications, Electrical: Acoustic Wave Systems and
Devices, subclass 141 for underwater vibration transducers.
381, Electrical Audio Signal Processing Systems and Devices,
150 for telephone transmitters and receivers using
magnetostrictive or piezoelectric effects.
Subclass:
142
Multipath propagation:
This subclass is indented under subclass 141. Subject matter
wherein the initial direction of mechanical wave energy is
changed.
(1) Note. This subclass includes devices wherein changes in
propagation direction result from reflection, diffraction,
refraction, or mode conversion.
Subclass:
143
Spurious signal reduction:
This subclass is indented under subclass 142. Subject matter
including means to reduce undesired signal generation.
(1) Note. Spurious signals may be generated by reflection,
diffraction, refraction, or multiple mode generation.
Subclass:
144
Variable delay:
This subclass is indented under subclass 141. Subject matter
wherein the effective length of the structure for
transmitting mechanical waves may be varied to provide a
variable delay.
(1) Note. Included in this subclass are devices wherein the
propagation velocity within the structure for transmitting is
a function of externally applied magnetic or electric fields,
control voltages, radiation, or mechanical forces.
Subclass:
145
Nonuniform propagation path:
This subclass is indented under subclass 141. Subject matter
in which the structure for transmitting mechanical waves is
tapered, stepped, or includes a hollow, composite,
anisotropic, or nonhomogeneous propagation path.
Subclass:
146
Helical propagation path:
This subclass is indented under subclass 141. Subject matter
wherein the structure for transmitting mechanical waves
includes a helical propagation path.
Subclass:
147
Propagation path has significant chemical or physical
properties:
This subclass is indented under subclass 141. Subject matter
wherein the material of the structure for transmitting
mechanical waves significantly affects the delay
characteristic.
(1) Note. The material, as a result if it is crystalline
structure or of its composition, may provide low losses, low
scattering, low dispersion, controlled dispersion, increased
power handling capabilities, or temperature stability.
(2) Note. Included in this subclass are devices wherein the
structure for transmitting mechanical waves is polarized,
semiconductive, gyromagnetic, ferroelectric, superconductive,
magnetoelastic, or is capable of magnetostatic wave
propagation.
Subclass:
148
Including magnetostrictive transducers:
This subclass is indented under subclass 141. Subject matter
wherein the conversion of electrical to mechanical energy or
the conversion of mechanical to electrical energy is
dependent on the magnetostrictive effect.
(1) Note. Magnetostrictive effect may be defined as the
change in dimensions of a body when subjected to a magnetic
field.
Subclass:
149
Significant transducer structure:
This subclass is indented under subclass 141. Subject matter
not classifiable in other subclasses indented thereunder
where the transducers used for electromechanical conversion
are structured or dimensioned to provide high efficiency
conversion, impedance matching, mode conversion, shock
resistance, or nonreflective properties.
Subclass:
150
Delay lines including elastic surface wave propagation
means:
This subclass is indented under subclass 24. Subject matter
wherein structure is provided for converting electric waves
to surface acoustic waves, transmitting the surface acoustic
waves to a means for reconverting the acoustic waves to
electrical waves.
(1) Note. This subclass is limited to devices where
significant acoustic wave transmission is along the free
surface of the transmission media.
(2) Note. The delay is due to the lower velocity of the
waves along the free surface of the transmission means. No
significant wave transmission is realized through the
interior of the transmission.
(3) Note. The transmission media may comprise either flat
or curved surfaces of a piezoelectric medium or a
nonpiezoelectric medium having a surface coating of
piezoelectric material.
SEE OR SEARCH THIS CLASS, SUBCLASS:
193 for filters employing surface acoustic waves.
Subclass:
151
Spurious signal or mode cancellation means:
This subclass is indented under subclass 150. Subject matter
including structure to reduce the effects of spurious
mechanical or electric wave signals or modes on the output
signal of the delay line.
(1) Note. Spurious modes or signals may result from
reflections of elastic surface waves, undesired conversion of
surface wave modes to bulk wave modes, nonlinearity of the
means for transmitting surface waves, or from undesired
capacitive coupling.
(2) Note. The mode cancellation means may include acoustic
absorbers, shielding electrodes, obstacles in the surface
acoustic wave path, or surface wave propagation substrates
having anisotropic propagation properties.
Subclass:
152
Variable delay:
This subclass is indented under subclass 150. Subject matter
including means for varying the delay.
(1) Note. Delay variation may be achieved by mechanical
translation of the input and output transducers used for
electromechanical conversion or by including surface wave
propagation substrates whose delay properties are altered by
incident radiation, electron bombardment, or by the
application of external field, forces, or control voltages.
(2) Note. The substrate material may include materials or
coatings which are both semiconductive and piezoelectric, are
both photosensitive and piezoelectric, or undergo significant
dimensional changes or deformation as a function of
externally applied heat or mechanical stress.
Subclass:
153
Including discontinuities within propagation means:
This subclass is indented under subclass 150. Subject matter
wherein abrupt modifications are included in the elastic
surface wave path so as to alter the delay or transmission
characteristics of the path.
(1) Note. Such discontinuities may serve as reflectors,
deflectors, diffractors, phase modifiers, or mode
converters.
(2) Note. Transducers distributed along the wave
transmission path to provide signal tapping functions (rather
than wave perturbation) are not included here.
Subclass:
154
Significant transmitting or receiving transducer structure:
This subclass is indented under subclass 150. Subject matter
wherein the transducers required for electromechanical wave
conversion have structural attributes, relative orientation,
spacing, or other structural organization critical with
respect to contributing to desired wave delay or wave
transmission characteristics.
(1) Note. Delay lines of the elastic surface wave type
which include transducer structures providing spurious signal
or mode cancellation functions are not classified here but
are classified in subclass 151.
Subclass:
155
Temperature stabilization compensation:
This subclass is indented under subclass 150. Subject matter
wherein the materials or structural elements included in the
delay lines reduce the delay time variations caused by
ambient temperature change.
Subclass:
156
Delay lines including long line elements:
This subclass is indented under subclass 24. Subject matter
having distributed parameters and including significant
structure for retarding wave energy a predetermined period of
time over a range of frequencies and systems within the class
definition which include such networks.
(1) Note. The time period may be constant over the range of
frequencies or proportional to the frequency (e.g., the time
of delay may be greater for the higher frequency).
SEE OR SEARCH THIS CLASS, SUBCLASS:
138 for delay structures wherein the wave energy to be
retarded propagates along line elements which include both
distributed and lumped elements.
202 for wave filters including long line elements.
236 for long lines.
245 for long line elements and components.
SEE OR SEARCH CLASS:
343, Communications: Radio Waves Antennas, subclass 778 for
plural waveguide-type antennas with phasing.
Subclass:
157
Waveguide:
This subclass is indented under subclass 156. Subject matter
wherein the structure for retarding energy propagates
electrical waves having an electric or magnetic field
component extending in the direction of propagation.
(1) Note. The waveguide may be a hollow dielectric or metal
tube or a solid dielectric rod, the wave energy being
propagated along the interior of the tube or rod and confined
or bounded by the tube or rod.
Subclass:
158
Including ferrite means:
This subclass is indented under subclass 157. Subject matter
including ferrite within the waveguide.
(1) Note. The ferrite is usually biased by a fixed or
variable external magnetic field so as to determine the
magnitude of wave retardation.
Subclass:
159
Having mechanically movable delay control means:
This subclass is indented under subclass 157. Subject matter
wherein the magnitude of wave retardation is adjusted by a
movable dielectric or conductive member within or proximate
to the waveguide.
Subclass:
160
Coaxial line:
This subclass is indented under subclass 156. Subject matter
wherein the structure for retarding wave energy is a
transmission line in which one conductor surrounds the other,
the two having a common longitudinal axis.
Subclass:
161
Planar line structure (e.g., stripline):
This subclass is indented under subclass 156. Subject matter
wherein the structure for retarding wave energy is a
transmission line including two or more spaced planar
conductors.
(1) Note. The planar line structure for classification here
may be of the stripline type, the microstrip type, or the
slot line type.
Subclass:
162
Helical line structures and lines developed from a helical
structure:
This subclass is indented under subclass 156. Subject matter
wherein the structure for retarding wave energy is a
transmission line including at least one conductor having a
helical configuration or a configuration developed from a
helix.
Subclass:
163
Having plural concentric helices:
This subclass is indented under subclass 162. Subject matter
wherein the structure for retarding wave energy is a
transmission line including two or more concentric helical
conductors.
Subclass:
164
Control of delay with semiconductive means:
This subclass is indented under subclass 156. Subject matter
wherein the conductivity state of a semiconductive means
associated with the delay line controls the magnitude of wave
retardation.
(1) Note. The semiconductive means may include switching
diodes, varactor diodes, or bulk effect semiconductors.
Subclass:
165
Frequency or time domain filters and delay lines utilizing
charge transfer devices:
This subclass is indented under subclass 24. Subject matter
for filtering or delaying wave energy wherein components of
signals to be filtered or delayed are sensed, charge samples
corresponding to the magnitude and/or phase of the signals
are developed, the charges are sequentially transferred at a
predetermined rate, and the charges are eventually sampled or
sensed to develop filtered and/or delayed output signals.
Subclass:
166
Time domain filter:
This subclass is indented under subclass 24. Subject matter
for filtering wave energy utilizing a tapped delay line
wherein a required impulse response is synthesized by
weighting and/or summing signals derived at the tap points.
Subclass:
167
Frequency domain filters utilizing only lumped parameters:
This subclass is indented under subclass 24. Subject matter
having only parameters which may be considered as
concentrated at one point and permitting free transmission of
electric waves of a single frequency or band of frequencies
(which may include zero frequency) while attenuating
substantially electric waves having other frequencies, or
attenuating substantially electric waves of a single
frequency or band of frequencies (which may include zero
frequency) while permitting free transmission of electric
waves having other frequencies, and systems within the class
definition which include such networks.
(1) Note. Tuners, which are closely analogous to the wave
filters in this class, are classified in Class 334, Tuners.
The tuners usually found in Class 334 consist of a lumped
inductance and capacitance element together with structure
means to vary either or both elements in order to change the
mean resonant frequency of the tuner. The tuners in Class
334 may include one or more long line elements in addition to
a lumped inductance or capacitance element, or the tuner may
consist of a distributed parameter type tuning unit which is
adjusted in discrete, distinct steps. Two or more
distributed parameter type tuner units which are of the
continuously variable type and which are ganged together
mechanically and/or electrically so as to have their mean
resonant frequency adjusted in unison are properly classified
in Class 334. Where only the bandwidth of the filter is
varied without varying the mean resonant frequency,
classification is in this class (333).
(2) Note. Filters combined with circuits having other
functions classified in other classes are excluded and will
be bound in other classes. See the classes referred to under
"Search Class" below. Note the exception in the case of a
mere current and or voltage control network combined with a
filter in (4) Note.
(3) Note. Filters which include an active element are
excluded. See Class 327, particularly subclasses 552+ where
the active element is an electron tube or a transistor. Note
that Class 327 includes some transversal filters.
(4) Note. Filters in combination with means merely to
control the magnitude of the current and/or voltage in the
network are included in this and the indented subclasses.
SEE OR SEARCH THIS CLASS, SUBCLASS:
1 for plural channel systems which include filters and for
filters with plural input and/or output terminals.
19 for differentiating or integrating networks which are
analogous to wave filters.
20 for wave shaping networks which are analogous to wave
filters and which may include wave filters.
28 for equalizing networks which are analogous to wave
filters.
100 where the filter includes branching means (e.g., a
single input with plural outputs).
124 for resonant filter networks for matching the impedance
in branched circuits, and branched circuits with line
sections analogous to wave filters for impedance matching
purposes.
157 for delay networks which are analogous to wave filters.
202 for long lines having frequency discriminating
properties.
219 for resonators including those with tuning means.
SEE OR SEARCH CLASS:
74, Machine Element or Mechanism, subclass 1 for mechanical
wave filters for transmitting mechanical waves of a
particular frequency or band of frequencies.
84, Music, 1.19, 621, 622, 699+ or 736 for electrical
systems used in musical instruments to produce musical tones
which include wave filters or tuners.
178, Telegraphy, 2 for telegraph systems involving wave
filters; and particularly subclass 47 and indented subclasses
for harmonic or reed type selective systems; subclass 49 for
superposed current systems with frequency selection means.
181, Acoustics, 175 for sound filters.
307, Electrical Transmission or Interconnection Systems,
particularly subclass 105 for electrical distribution
systems including wave filters and subclass 132 for circuit
interrupting systems having filters to eliminate the higher
frequency components.
322, Electricity: Single Generator Systems, subclass 58 for
generator controls with means for suppressing or minimizing
undesired frequencies.
323, Electricity: Power Supply or Regulation Systems. Note
that Class 323 provides for "filters" which control only the
voltage and/or current magnitude. If the circuit which
performs the filtering action is arranged only to "buck out"
or balance the undesired components, classification is in
Class 323.
327, Miscellaneous Active Electrical Nonlinear Devices,
Circuits, and Systems, particularly 552 for unwanted signal
suppression by an active filter which may utilize a
transistor or an electron tube.
329, Demodulators, appropriate subclasses for a demodulator
which includes tuning or filtering.
330, Amplifiers, 302 for transistor amplifiers with
frequency responsive means; subclass 86 for amplifiers having
an automatically variable impedance in the feedback path;
subclass 94 for amplifiers having a frequency responsive
means in a cathode feedback path; subclass 109 for amplifiers
with frequency responsive means in the feedback path;
subclass 143 for amplifiers with a thermal impedance in the
signal path which may be automatically variable; subclasses
144+ for amplifiers having an automatically variable
impedance in the signal path including such subject matter
involving a variable reactance for automatically tunable or
selective circuits; subclass 154 for cascaded amplifiers
including a resonant circuit; subclass 155 for amplifier
circuits including means for unicontrol of the coupling
circuits; and subclasses 157+ and 192+ for amplifier systems
with significant interstage, input and output coupling which
may include wave filters.
331, Oscillators, appropriate subclasses, particularly
subclass 43, 76, 77, 110, and 138+ for oscillators utilizing
a wave filter as an element thereof.
332, Modulators, appropriate subclasses for modulators
involving wave filters.
340, Communications: Electrical, 825.71 for selective
communication systems which are frequency responsive.
343, Communications: Radio Wave Antennas, subclass 722 for
antennas with a lumped reactance filter in the active
antenna; and subclasses 745+ for antennas with a variable
reactance for tuning the antenna.
363, Electric Power Conversion Systems, 39 for conversion
systems in combination with a filter.
370, Multiplex Communications, appropriate subclasses,
particularly subclass 488 and 497 for a multiplex system
which includes connecting filters.
379, Telephonic Communications, appropriate subclasses for
telephone systems involving wave filters; and particularly
subclass 2 and indented subclasses for composite systems
utilizing wave filters; and subclasses 78, 79, 80, and 174
for anti-inductive systems and devices with wave
discriminating properties.
381, Electrical Audio Signal Processing Systems and Devices,
98 for audio signal processing devices and systems having
frequency control.
455, Telecommunications, 91 for transmitters involving wave
filters; and subclasses 150.1+ and 296+ (especially subclass
307) for radio receivers with filters or tuners.
Subclass:
168
Including recurrent sections:
This subclass is indented under subclass 167. Subject matter
wherein similar or equivalent elements or groups of elements
are cascaded.
(1) Note. Examples of filters classified here are ladder
network or reiterations of "T" or "pi" networks whose formats
are topos:graphically similar but whose
parameters may not be equal in every reiteration. Examples
of such filters included are:
[figure] [figure]
Subclass:
169
Wheatstone or lattice type:
This subclass is indented under subclass 167. Subject matter
having four impedance branches connected in series to form a
closed circuit, two nonadjacent junction points serving as
input terminals while the remaining two junction points serve
as output terminals.
(1) Note. Two of the impedance branches may be formed by a
transformer winding having a mid-tap, the mid-tap forming one
of the input or output terminals, and the other winding of
the transformer forming the output or input connecting means.
See Fig. 4 below.
(2) Note. Included are for example:
[figure] [figure] [figure] [figure]
SEE OR SEARCH THIS CLASS, SUBCLASS:
117 for hybrid-type networks used in branched circuits.
133 for similar networks which include electromechanical
transducer elements.
SEE OR SEARCH CLASS:
236, Automatic Temperature and Humidity Regulation, 69, 74,
78, and 91 for temperature regulating systems which include
impedance bridge networks as the control means.
318, Electricity: Motive Power Systems, subclass 294 for
motor reversing systems wherein the armature current reversal
means includes an impedance bridge network; and subclass 535
for motor field circuit control systems which include an
impedance bridge network; and subclasses 663+ for position
servomechanisms which may include a bridge in the error
detector circuit.
322, Electricity: Single Generator Systems, subclass 77 for
single generator systems where the generator field circuit is
controlled by means of an impedance bridge network.
323, Electricity: Power Supply or Regulation Systems,
subclass 365 for voltage magnitude control systems involving
Wheatstone bridge arrangements.
324, Electricity: Measuring and Testing, appropriate
subclasses, especially 98 and 101+ for electric measuring
and testing systems using impedance bridge arrangements.
330, Amplifiers, subclass 146 for amplifier systems having
an amplifier in one arm of a bridge; and subclass 175 for
amplifier systems having a lattice or Wheatstone bridge
network in the signal coupling means.
331, Oscillators, subclass 110 and 138+ for bridge type
oscillation generation systems in general.
332, Modulators, subclass 172 for amplitude modulating
systems of the bridge type having conjugate input and
output.
363, Electric Power Conversion Systems, 148 for phase
conversions arranged as a bridge.
Subclass:
170
Bridge type:
This subclass is indented under subclass 167. Subject matter
having an impedance path containing a plurality of filter
impedance units connected in series relation between an input
and an output terminal, the filter also having a shunt
connection containing an impedance connected to the junction
of the series filter impedance units and to the other side of
the line between the input and output terminals, an impedance
path being connected to different ones of the series
impedance units at points other than the junction between the
units.
(1) Note. The last named impedance path is therefore in
parallel with at least a portion of the series connected
filter impedance units in the input circuit and the output
circuit. The last named impedance path may include an
inductive coupling.
(2) Note. Examples of filter networks included and excluded
are:
[figure] [figure] [figure]
SEE OR SEARCH CLASS:
331, Oscillators, subclass 142 in particular for bridge-type
oscillators utilizing a double T bridge of the RC or RL
element type.
Subclass:
171
With variable response:
This subclass is indented under subclass 170. Subject matter
wherein at least one of the filter impedance units is made
adjustable in order to vary the response of the filter.
Subclass:
172
RC or RL type:
This subclass is indented under subclass 167. Subject matter
wherein the filter parameters are limited to combinations of
resistance and capacitance or to combinations of resistance
and inductance.
Subclass:
173
Synchronous filters:
This subclass is indented under subclass 167. Subject matter
wherein the parameters of the filter are cyclically connected
or disconnected.
(1) Note. The response (e.g., bandwidth, center frequency,
harmonic rejection, etc.) is determined both by the magnitude
of the filter parameters and by the rate at which the
connections or disconnections are made.
Subclass:
174
With variable response:
This subclass is indented under subclass 167. Subject matter
wherein at least one of the filter parameters is made
adjustable in order to vary the response of the filter.
Subclass:
175
Resonant, discrete frequency selective type:
This subclass is indented under subclass 167. Subject matter
which include resonant series and/or parallel inductance and
capacity networks which offer a low impedance path to energy
of a particular frequency or of a plurality of separate
discrete frequencies and/or offer a high impedance path to
energy of a particular frequency or of a plurality of
discrete frequencies.
(1) Note. This subclass includes filters under its
definition in which means are incorporated for sharpening the
tuning of the resonant circuits as by compensating for the
resistance in such circuits.
(2) Note. The filters in this subclass are especially
designed to pass only a single discrete frequency or a
plurality of discrete frequencies but not a continuous band,
or to eliminate one or more discrete frequencies from a band
of frequencies.
SEE OR SEARCH THIS CLASS, SUBCLASS:
197 for similar filters utilizing electromechanical
transducers.
SEE OR SEARCH CLASS:
330, Amplifiers, 302 for transistor amplifiers with
frequency responsive coupling; subclasses 94 and 109 for
amplifiers with frequency responsive feedback means; subclass
154 for cascaded amplifiers having a resonant means in an
interstage coupling circuit; subclasses 157+, 185+, and 192+,
particularly subclasses 167, 189, and 196 for coupling
circuits with resonant circuit means.
331, Oscillators, subclass 76 for oscillators, combined with
an output coupling network including a harmonic selecting
filter.
334, Tuners, appropriate subclasses for tuners adapted to be
used in wave energy apparatus, also see the reference note to
Class 334 in the search notes of subclass 167.
Subclass:
176
Including specific frequency rejection means:
This subclass is indented under subclass 175. Subject matter
which include circuitry, provided for rejecting harmonics or
for providing discrete transmission zeroes or attenuation
poles within, at the edge of, or outside of, a prescribed
filter pass band.
Subclass:
177
Transformer coupled:
This subclass is indented under subclass 167. Subject matter
which include a mutual inductance link of the lumped type
between the input and output of the filter.
(1) Note. The filters in this subclass are usually of the
band-pass type, wherein the band-pass effect is due to the
coupling between resonant circuits (e.g., intermediate
frequency transformer systems with more than critical
coupling between tuned primary and secondary circuits). The
mutual inductance link need not be between the resonant
circuits of the filter but may constitute the input or output
coupling, the coupling between the resonant circuits being
capacitive.
(2) Note. Wave filters wherein the mutual inductance link
is of the long line type are not in this subclass but will be
found in subclasses 125+ for branched circuit impedance
matching networks; subclass 26 for balanced to unbalanced
circuit conversion; subclasses 33+ for impedance matching
networks; and subclasses 202+ for wave filters.
SEE OR SEARCH THIS CLASS, SUBCLASS:
197 for electromechanical transducer-type filters involving
transformer coupling.
SEE OR SEARCH CLASS:
323, Electricity: Power Supply or Regulation Systems,
subclass 247, 301, 305, 328, and 355 for current and/or
voltage magnitude control systems including transformers, and
for miscellaneous transformer systems.
330, Amplifiers, subclass 154, 165+, 188+, and 195+ for
amplifiers having transformer coupling.
336, Inductor Devices, appropriate subclasses for
transformers which are not designed to be frequency
responsive.
379, Telephonic Communications, 443 for induction coils
combined with the structure of telephone instruments.
Subclass:
178
Including bandwidth adjusting, shaping or stabilization
means:
This subclass is indented under subclass 177. Subject matter
wherein means are provided for adjusting the bandwidth or for
maintaining constant bandwidth when circuit parameters are
intentionally varied or when circuit parameters vary as a
result of fluctuations in ambient conditions.
Subclass:
179
With permeability tuning means:
This subclass is indented under subclass 177. Subject matter
wherein means are provided for varying the permeability of
the mutual inductance link.
Subclass:
180
With variable coupling means:
This subclass is indented under subclass 177. Subject matter
wherein means are provided to adjust the degree of coupling
between circuit elements or groupings of circuit elements.
(1) Note. This subclass includes means to vary either
inductive coupling, capacitive coupling, resistive coupling,
or any combinations of such coupling.
Subclass:
181
Smoothing type (e.g., direct current power supply filters or
decoupling filters):
This subclass is indented under subclass 167. Subject matter
having shunt capacitance or series inductance, or both,
usually designed to pass direct current and to reduce the
effect of any undesired alternating or pulsating current
superimposed on the direct current or to pass direct current
and low frequency alternating current or pulsating current
and to reduce the effect of an undesired higher frequency
alternating or pulsating current.
(1) Note. Such filters usually have no resonant
relationship between the inductance and capacitance over the
range of applied frequencies.
(2) Note. These filters are usually of the "brute force"
type, utilizing an excess inductance and/or capacitance.
They are generally low pass, being adapted to pass direct
current and to reduce the effect of any undesired alternating
current superimposed on the direct current.
(3) Note. Included are systems with a smoothing-type filter
combined with a passive network means to regulate the current
or voltage applied to or abstracted from the filter.
SEE OR SEARCH CLASS:
323, Electricity: Power Supply or Regulation Systems. If
the circuit which performs the smoothing action does so only
by "bucking out" or balancing the undesired components,
classification is in Class 323.
330, Amplifiers, subclass 141 for amplifiers having
smoothing circuits in the bias control path; subclass 142 for
amplifiers including self-biasing circuits; and subclasses
199+ for amplifiers having significant power or bias supply
means which may include significant details of smoothing
filters.
363, Electric Power Conversion Systems, 39 for conversion
systems, (i.e., rectification or decertification) in
combination with smoothing-type filters.
Subclass:
182
Feedthrough type:
This subclass is indented under subclass 181. Subject matter
structured so as to include a central conductor
concentrically surrounded by a capacitive or inductive
element or by combinations of such elements.
(1) Note. These filter structures are usually adapted to be
mounted in a partition, wall, or bulkhead, or to be mounted
within a connector assembly.
Subclass:
183
Resiliently mounted components:
This subclass is indented under subclass 182. Subject matter
wherein the central conductor or the inductive or capacitive
elements are engaged to each other by resilient mounting
structures.
(1) Note. The resilient mounting structures may include
conductive or nonconductive elements providing for relative
ease in assembling or disassembling of filter components
and/or for providing relative ease in assembling filter
components within a connector structure.
Subclass:
184
Monolithic structure:
This subclass is indented under subclass 181. Subject matter
wherein inductive or capacitive elements are integrated on or
within a common substrate or support.
Subclass:
185
Having significant physical structure:
This subclass is indented under subclass 167. Subject matter
wherein the geometry of individual parameters or the physical
distribution of such parameters is critical to obtaining the
desired delay.
(1) Note. Included here would be inductive parameters
having a specific core structure and/or winding geometry
(i.e., low capacity windings).
Subclass:
186
Electromechanical filter:
This subclass is indented under subclass 24. Subject matter
including at least one electrical wave driven mechanical
vibrator as a frequency determining element, providing free
transmission of electric waves of a single frequency or band
of frequencies (which may include zero frequency) while
attenuating substantially electric waves having other
frequencies, or attenuating substantially electric waves of a
single frequency or band of frequencies (which may include
zero frequency) while permitting free transmission of
electric waves having other frequencies, and systems within
the class definition which include such networks.
(1) Note. In many of the devices in this and the indented
subclass, the electrical wave energy is converted into
mechanical energy which is transmitted to a means for
reconverting the mechanical energy to electrical wave energy.
The mechanical energy transmitting means may be a bar, rod,
fluid, etc. The mechanical transmission member determines
the frequency of the energy transmitted.
SEE OR SEARCH THIS CLASS, SUBCLASS:
148 for delay networks of the electromechanical transducer
type which are analogous to wave filters.
SEE OR SEARCH CLASS:
178, Telegraphy, subclass 49 for telegraph systems utilizing
vibrating elements for transmitting undulating currents.
181, Acoustics, 207 for mufflers and sound filters, see
subclass 207 for rods designed to transmit mechanical
vibrations and to damp out other mechanical vibrations and
designed to act as mechanical filters.
310, Electrical Generator or Motor Structure, 311 for
piezoelectric devices; and subclass 26 for the miscellaneous
magnetostrictive devices.
318, Electricity: Motive Power Systems, subclass 118 for
magnetostrictive motors; and subclass 116 for piezoelectric
motors.
322, Electricity: Single Generator Systems, in the
appropriate subclasses for electromechanical transducers of
the motor generator type.
323, Electricity: Power Supply or Regulation Systems,
subclasses 201-204 for dynamoelectric systems.
330, Amplifiers, subclass 174 for amplifier systems having
an electromechanical transducer coupling element;
magnetostrictive means in an amplifier system are classified
in subclass 60.
331, Oscillators, appropriate subclasses particularly
subclass 73, 116, 139, and 154+ for oscillators employing an
electromechanical resonator or transducer as an element
thereof.
336, Inductor Devices, subclass 20 for inductors having
magnetostrictive structure.
367, Communications, Electrical: Acoustic Wave Systems and
Devices, subclass 141 for underwater vibration transducers.
381, Electrical Audio Signal Processing Systems and Devices,
337 for telephone transmitters and receivers with mechanical
sound amplifying means (e.g., harmonic vibrators); and
subclasses 190 and 355+ for telephone transmitters and
receivers using magnetostrictive effects.
Subclass:
187
Using bulk mode piezoelectric vibrator:
This subclass is indented under subclass 186. Subject matter
wherein the wave driven mechanical resonator is a
piezoelectric body subject to changes in its transverse
and/or longitudinal dimension(s) under the influence of an
external electric field.
(1) Note. The dimensional deformations of the piezoelectric
vibrator are accompanied by mechanical bulk wave mode
resonances, such resonances may be of the transverse,
longitudinal, sheer, radial, or plate mode type.
(2) Note. Excluded from this subclass are surface acoustic
wave filters wherein mechanical deformation is realized
substantially only along the free surface of a piezoelectric
body and no significant bulk mode resonance effects are
realized.
SEE OR SEARCH CLASS:
310, Electrical Generator or Motor Structure, subclass 323.19
for a piezoelectric element forming a resonant structure
used to convert electric energy into sound energy or a
piezoelectric element combined with specific means to conduct
sound energy.
Subclass:
188
With means for varying response:
This subclass is indented under subclass 187. Subject matter
wherein the filter bandwidth, center frequency, or phasing
may be adjusted by mechanically or electrically variable
parameters.
Subclass:
189
Plural coupled vibrators:
This subclass is indented under subclass 187. Subject matter
wherein a plurality of vibrators are electrically or
mechanically intercoupled so as to provide a composite
response dependent on the contribution of each vibrator.
Subclass:
190
Lattice structure:
This subclass is indented under subclass 189. Subject matter
having four circuit element branches connected in series to
form a closed circuit, two nonadjacent junction points
serving as input terminals while the remaining two junctions
serve as output terminals.
(1) Note. At least two of the circuit element branches
include a piezoelectric vibrator.
(2) Note. Two of the circuit branches may be formed by a
transformer winding having a mid-tap, the mid-tap forming one
of the input or output terminals, and the other winding of
the transformer forming the output or input connecting means.
See Fig. 4 below.
(3) Note. Included are for example:
[figure] [figure] [figure] [figure]
Subclass:
191
Monolithic structure:
This subclass is indented under subclass 189. Subject matter
wherein a plurality of coupled vibrators are formed on a
common piezoelectric body.
Subclass:
192
With electrical coupling:
This subclass is indented under subclass 191. Subject matter
wherein the vibrators include electrical intercoupling.
(1) Note. The vibrators may also include mechanical
coupling.
Subclass:
193
Using surface acoustic waves:
This subclass is indented under subclass 186. Subject matter
wherein mechanical wave energy within a desired frequency
band is transmitted in the form of acoustic waves propagating
principally along a free surface or a guiding substrate.
(1) Note. The substrate is usually piezoelectric or
comprises a surface coated with material having piezoelectric
properties.
(2) Note. The surface waves are excited by transducers
having a desired frequency selectively.
Subclass:
194
Including spurious signal prevention or reduction means:
This subclass is indented under subclass 193. Subject matter
including structure for minimizing undesired electrical or
mechanical mode coupling.
Subclass:
195
With wave-modifying means (e.g., reflectors, resonators,
diffractors, multistrip couplers, etc):
This subclass is indented under subclass 193. Subject matter
including structure for modifying the amplitude, phase
velocity, or propagation path of surface acoustic wave energy
along the wave propagation path.
(1) Note. Included here are structures to establish surface
acoustic wave resonance on selected portions of the
propagation path.
Subclass:
196
With response weighting means:
This subclass is indented under subclass 193. Subject matter
including significant structure for adjusting the amplitude
and/or phase versus frequency transmission characteristics of
the filters.
Subclass:
197
Plural mechanically coupled bar, plate or rod type resonating
means:
This subclass is indented under subclass 186. Subject matter
wherein plural mechanical vibrators structured in the form of
bars, rods, or plates are mechanically intercoupled.
(1) Note. The individual vibrators may have the same or
different periods of vibration.
Subclass:
198
Plural interresonator coupling paths:
This subclass is indented under subclass 197. Subject matter
wherein some of the vibrators are coupled to each other along
a plurality of mechanical wave coupling paths.
(1) Note. As an example, two rods or plates are
intercoupled at more than one point (i.e., two end points of
one vibrator are mechanically coupled to two end points of a
second vibrator).
Subclass:
199
Plural mechanically coupled disk resonators:
This subclass is indented under subclass 197. Subject matter
wherein plural disk-shaped vibrators are mechanically
intercoupled.
Subclass:
200
Reed or fork-type resonators:
This subclass is indented under subclass 186. Subject matter
wherein the vibrators are either elongated planar flexural
mode structures having a relatively large ratio of length to
width and thickness or are structured so as to resemble the
tines of a fork.
Subclass:
201
Magnetostrictive wave transmission path:
This subclass is indented under subclass 186. Subject matter
wherein mechanical wave energy is transmitted by a vibrator
comprised of magnetostrictive material.
Subclass:
202
Wave filters including long line elements:
This subclass is indented under subclass 24. Subject matter
including elements having distributed parameters and
permitting free transmission of electric waves of a single
frequency or band of frequencies (which may include zero
frequency) while attenuating substantially electric waves
having other frequencies, or attenuating substantially
electric waves of a single frequency or band of frequencies
(which may include zero frequency) while permitting free
transmission of electric waves having other frequencies, and
systems within the class definition which include such
networks.
(1) Note. Tuners, which are closely analogous to the wave
filters in the class, are classified in Class 334, Tuners.
The tuners in Class 334 may include one or more long line
elements in addition to a lumped inductance or capacitance
element, or the tuner may consist of a distributed parameter
type tuning unit which is adjusted in discrete, distinct
steps. Two or more distributed parameter type tuner units
which are of the continuously variable type and which are
ganged together mechanically and/or electrically so as to
have their mean resonant frequency adjusted in unison are
properly classified in Class 334. Where only the bandwidth
of the filter is varied without varying the means resonant
frequency, classification is in this class (333).
(2) Note. Filters combined with circuits having other
functions classified in other classes are excluded and will
be found in other classes. See the classes referred to under
"Search Class" below. Note the exception in the case of a
mere current and/or voltage control network combined with a
filter in (4) Note.
(3) Note. Filters which include an active element are
excluded. See Class 327, particularly subclasses 552+ where
the active element is an electron tube or a transistor. Note
that Class 327 includes some transversal filters.
(4) Note. Filters in combination with means merely to
control the magnitude of the current and/or voltage in the
network are included in this and the indented subclass.
SEE OR SEARCH THIS CLASS, SUBCLASS:
1 for plural channel systems which include filters and for
filters with plural input and/or output terminals.
19 for differentiating or integrating networks which are
analogous to wave filters.
20 for wave shaping networks which are analogous to wave
filters and which may include wave filters.
28 for equalizing networks which are analogous to wave
filters.
100 where the filter includes branching means (e.g., a
single input with plural outputs).
126 for resonant filter networks for matching the impedance
in branched circuits, and branched circuits with line
sections analogous to wave filters for impedance matching
purposes.
132 for branched circuits which include filters.
156 for delay networks having long line elements analogous
to wave filters.
219 for resonators.
236 for long lines.
245 for long line elements.
SEE OR SEARCH CLASS:
327, Miscellaneous Active Electrical Nonlinear Devices,
Circuits, and Systems, particularly 552 for unwanted signal
suppression by an active filter which may utilize a
transistor or an electron tube.
330, Amplifiers, 53 for amplifier systems with long line
element coupling means.
331, Oscillators, 96 which include distributed parameters.
Subclass:
203
Digital structure:
This subclass is indented under subclass 202. Subject matter
wherein the filter structure includes a plurality of
electromagnetically coupled bar-or strip-type resonator
sections aligned perpendicularly to the direction of wave
propagation.
Subclass:
204
Stripline or microstrip:
This subclass is indented under subclass 202. Subject matter
wherein the filter structure includes a long line of the type
having planar conductors.
(1) Note. Examples of such lines are strip-lines, wherein a
flat conductor is included between two ground planes, or
microstrip lines, wherein a flat conductor coacts with a
single ground plane.
Subclass:
205
Tunable:
This subclass is indented under subclass 204. Subject matter
wherein the filter structure includes electrically or
mechanically variable parameters to provide an adjustable
amplitude versus frequency characteristic.
Subclass:
206
Coaxial:
This subclass is indented under subclass 101. Subject matter
including a line structure comprising a conductor coaxially
aligned with an outer cylindrical conductive sheath.
Subclass:
207
Tunable:
This subclass is indented under subclass 106. Subject matter
wherein the filter structure includes electrically or
mechanically variable parameters to provide an adjustable
amplitude versus frequency characteristic.
Subclass:
208
Waveguide:
This subclass is indented under subclass 202. Subject matter
wherein the filter structure includes a hollow dielectric
tube, a hollow metal tube, or a solid dielectric designed to
propagate electrical waves having an electric or magnetic
field component extending in the direction of propagation and
wherein the outer surfaces of the tube or solid dielectric
serve as boundaries for the electromagnetic fields.
(1) Note. Included in this subclass would be filters
employing dielectric rods or dielectric clad conductors
wherein the propagation of energy is substantially confined
to the immediate neighborhood of the rod or dielectric clad
conductor.
Subclass:
209
Tunable:
This subclass is indented under subclass 208. Subject matter
wherein the filter structure includes electrically or
mechanically variable parameters to provide an adjustable
amplitude versus frequency characteristic.
Subclass:
210
Including evanescent guide sections:
This subclass is indented under subclass 108. Subject matter
wherein a waveguide section has reduced or negligible
transmission due to the waveguide section being operated
below its frequency cutoff point.
Subclass:
211
Including frequency selective absorbing means:
This subclass is indented under subclass 208. Subject matter
wherein means are provided to dissipate or absorb wave energy
of a given frequency or band of frequencies.
Subclass:
212
Including directly coupled resonant sections:
This subclass is indented under subclass 208. Subject matter
wherein the filter structure includes resonant cavities
directly coupled by slots or irises.
Subclass:
213
NEGATIVE RESISTANCE OR REACTANCE NETWORKS OF THE ACTIVE
TYPE:
This subclass is indented under the class definition.
Systems including active elements for producing, across at
least two of the system terminals, a negative resistance
and/or an inductance or capacitance which may be positive or
negative.
(1) Note. This subclass does not include dynamoelectric
machine systems which are used as a reactance element.
SEE OR SEARCH CLASS:
307, Electrical Transmission or Interconnection Systems, 401
for nonlinear reactance systems which may exhibit negative
resistance characteristics.
323, Electricity: Power Supply or Regulation Systems,
subclasses 212-219 for phase shift systems.
327, Miscellaneous Active Electrical Nonlinear Devices,
Circuits, and Systems, appropriate subclasses for
miscellaneous circuits utilizing negative resistance
devices.
330, Amplifiers, 75 for feedback amplifiers of the vacuum,
tube type, particularly subclasses 82, 93, 101, 104, and 112
for positive feedback amplifiers; and subclasses 291+ for
transistor feedback amplifiers.
331, Oscillators, 86 for magnetron-type oscillators which
may utilize negative resistance effects; subclass 115 for
transistor oscillators of the negative resistance type;
subclasses 126+ for oscillators utilizing the negative
resistance characteristic of a gaseous space discharge; and
subclasses 132+ for negative resistance or negative
transconductance oscillators in general. Subclasses 1+ of
Class 331 provide for automatic frequency stabilized
oscillators many of which utilize adjustable reactance tubes,
indented subclass 36 provides for particular frequency
control means (e.g., reactance tubes, saturable inductors,
etc.); and subclass 180 provides for oscillators in general
including frequency adjusting means of the reactance tube
type.
332, Modulators, particularly subclass 140 and 142+ for
reactance tubes in frequency modulators, subclasses 147+ for
reactance tubes in phase modulators, and subclass 175 for
reactance tubes in amplitude modulators.
334, Tuners, 14 for tuners utilizing reactance tube
networks.
Subclass:
214
Simulating specific type of reactance:
This subclass is indented under subclass 213. Subject matter
wherein a positive-valued inductance or capacitance is
produced.
Subclass:
215
Using gyrator:
This subclass is indented under subclass 214. Subject matter
employing a nonreciprocal circuit of the type that produces
at one point the positive inversion of the impedance at a
second point (i.e., a positive impedance inverter).
(1) Note. GYRATOR: A gyrator is a four-terminal, two-port
nonreciprocal network which may be defined as follows:
[figure]
wherein R[subscrpt]1[end subscrpt] and R[subscrpt]2[end
subscrpt] are transfer impedances whose product determines
the gyration constant K.
Subclass:
216
Having negative impedance:
This subclass is indented under subclass 213. Subject matter
wherein a negative-valued impedance is produced across two of
the system terminals.
Subclass:
217
Providing negative resistance:
This subclass is indented under subclass 216. Subject matter
wherein the negative impedance is a negative resistance.
Subclass:
218
FREQUENCY MULTIPLIERS:
This subclass is indented under the class definition.
Subject matter wherein the device has a single input and
single output and the frequency of the output wave is
normally a whole number multiple of the input frequency.
(1) Note. The device must be a long line element and use a
nonlinear solid-state device for multiplying.
Subclass:
219
RESONATORS (DISTRIBUTED PARAMETER TYPE):
This subclass is indented under the class definition.
Devices comprising conductive enclosures, cavities, or wave
transmission line sections of the two terminal types and
having distributed inductance and capacitance, the line
sections being terminated in other than the characteristic
impedance of the line sections, the devices presenting
resonant characteristics to the exciting source of wave
energy, and systems within the class definition which include
such devices.
(1) Note. This subclass includes resonators even if they
are provided with tuning means and designated as tuners.
SEE OR SEARCH THIS CLASS, SUBCLASS:
245 for long line elements which are terminated in other
than their characteristic impedance and which are
nonresonant, i.e., transmission line elements which are
effectively inductances or capacitances, such as being 1/8 of
a wave-length long.
SEE OR SEARCH CLASS:
315, Electric Lamp and Discharge Devices: Systems, 4 for
cathode-ray tubes which have structurally combined therewith
a resonant structure; subclasses 39+ for electronic tubes
having structurally combined therewith a resonant
transmission line; and subclasses 39.51+ and 40 for other
electronic tubes which include resonant structures.
330, Amplifiers, 53 for amplifiers having distributed
parameter coupling which may be resonant; subclass 45 for
electron beam type amplifiers having cavity resonator
coupling means; subclass 49 for amplifiers wherein the active
element is a tube having distributed parameter
characteristics which may be resonant.
331, Oscillators, subclass 5, 6+, 9, 79+, 86+, 93, and 96+
for oscillator systems utilizing distributed parameter
resonators as an element thereof.
332, Modulators, particularly 129 for resonators in
frequency modulators and subclasses 163+ for resonators in
amplitude modulators.
343, Communications: Radio Wave Antennas, subclass 723 for
single adjustable length electrically long linear antennas;
subclasses 745+ for antennas with a variable reactance for
tuning the antenna; subclasses 746 and 767+ for slot-type
antennas which may include resonator structure; subclasses
790+ for sleeve-type antennas; subclasses 793+ for balanced
doublet-type antennas which may have resonant
characteristics; subclasses 825+ for fractional, multiple, or
full wavelength-type antennas; and subclass 843 for antennas
having an appreciable wave-length dimension.
455, Telecommunications, 130 for radio receivers using
resonators, see particularly subclasses 325+ for frequency
conversion means with distributed parameter elements which
may be resonant.
Subclass:
219.1
Dielectric type:
This subclass is indented under subclass 219. Subject matter
where the resonator device is a dielectric material body in
which field configurations excited by the source of wave
energy are substantially confined therein.
Subclass:
219.2
Magnetic type:
This subclass is indented under subclass 219. Subject matter
where the resonator device possesses magnetic properties
responsive to the exciting source of wave energy.
Subclass:
220
Open wire or lecher line:
This subclass is indented under subclass 219. Subject matter
wherein the line section is of the parallel wire type
normally an integral number of half-wavelengths long so as to
set up standing waves on the section.
Subclass:
221
With tuning:
This subclass is indented under subclass 220. Subject matter
wherein the resonator has means which can be adjusted to
resonate or operate at a specified frequency.
Subclass:
222
Coaxial or shielded:
This subclass is indented under subclass 219. Subject matter
wherein the resonator is of the two conductor type having a
central conductor concentric with the resonator outer
conductor.
Subclass:
223
With tuning:
This subclass is indented under subclass 222. Subject matter
wherein the resonator has means which can be adjusted to
resonate or operate at a specified frequency.
Subclass:
224
Having movable element:
This subclass is indented under subclass 223. Subject matter
wherein the frequency is adjusted by a movable element.
Subclass:
225
Using movable shorting means:
This subclass is indented under subclass 224. Subject matter
wherein short-circuiting means is included with the coaxial
or shielded transmission line.
Subclass:
226
Using plunger, rod, or piston:
This subclass is indented under subclass 224. Subject matter
wherein the movable element is a plunger, rod, or piston.
Subclass:
227
Cavity resonator:
This subclass is indented under subclass 219. Devices and
systems where the resonator device is an enclosure or cavity
so constructed that the field configuration excited within
the boundaries of the device includes longitudinal as well as
transverse field components.
SEE OR SEARCH CLASS:
315, Electric Lamp and Discharge Devices: Systems, 5 for
cathode-ray tubes which have structurally combined therewith
a hollow resonant structure (e.g., waveguide hollow
resonator); subclasses 39+ for electronic tubes structurally
combined with a waveguide section; and subclasses 39.51+ and
40 for other electronic tubes structurally combined with
resonator structure (e.g., magnetrons).
330, Amplifiers, subclass 45 for electron beam tube
amplifiers coupled to a cavity resonator; and subclass 56 for
amplifiers, generally having a resonator of the waveguide,
cavity, or concentric line type.
331, Oscillators, subclass 5, 6+, 81+, 86+, 93, and 96 for
oscillator systems utilizing distributed parameter
resonators, which resonators may be of the cavity or hollow
waveguide type.
332, Modulators, particularly 129 for resonators in
frequency modulators and subclasses 163+ for resonators in
amplitude modulators.
343, Communications: Radio Wave Antennas, subclass 762 and
772+ for waveguide-type antennas; and subclass 771 for plural
slot-type antennas with waveguide coupling.
Subclass:
228
With mode suppressor:
This subclass is indented under subclass 227. Subject matter
wherein means are provided to minimize or substantially
eliminate extraneous modes of oscillation in cavity
resonators.
Subclass:
229
With temperature compensation:
This subclass is indented under subclass 227. Subject matter
wherein the cavity resonator has thermal compensation means
to substantially reduce the effects of temperature variations
on the operating frequency.
Subclass:
230
With coupling:
This subclass is indented under subclass 227. Subject matter
wherein significant structure is included for effecting the
transfer of oscillatory energy between the cavity resonator
and another circuit.
Subclass:
231
With tuning:
This subclass is indented under subclass 227. Subject matter
wherein the cavity has means whereby the cavity can be
adjusted to resonate or operate at a specified frequency.
Subclass:
232
Having movable element:
This subclass is indented under subclass 231. Subject matter
wherein the frequency is adjusted by a movable element.
Subclass:
233
Using movable wall:
This subclass is indented under subclass 232. Subject matter
wherein the movable element is a wall that moves or is
flexible.
Subclass:
234
Temperature compensated:
This subclass is indented under subclass 219. Subject matter
wherein the resonator has thermal compensation means to
substantially reduce the effects of temperature variations on
the operating frequency.
Subclass:
235
With tuning:
This subclass is indented under subclass 219. Subject matter
wherein the cavity of the resonator has means which can be
adjusted to resonate or operate at a specific frequency.
Subclass:
236
LONG LINES:
This subclass is indented under the class definition.
Structure providing a single channel of indefinite length for
conveying and guiding wave energy, and having distributed
electrical parameters so related or proportioned as to
determine the wave propagating characteristics of the
channel.
SEE OR SEARCH THIS CLASS, SUBCLASS:
12 for long lines with means to eliminate interference
currents therein or with means to minimize radiation
therefrom.
22 for dissipative terminations for transmission lines.
23 for artificial lines simulating a transmission line.
26 for coupling networks for connecting balanced to
unbalanced circuits or vice versa which include a long line
element.
27 for transmission lines with coupling networks at the
opposed ends.
33 for impedance matching networks which include a long line
element.
202 for filters which include a long line element.
SEE OR SEARCH CLASS:
174, Electricity: Conductors and Insulators, appropriate
subclasses for conductor structure other than loaded lines
and lines defined as having long line characteristics; see
subclass 27 and 113+ for parallel or twisted conductor
structures; subclasses 28 and 102+ for coaxial and shielded
cable structure; subclasses 32+ for anti-inductive conductor
structures; subclasses 37+ for underground conductor
structures; and subclasses 40+ for overhead conductor
structures.
178, Telegraphy, for telegraph transmission line systems; and
particularly 45 for loaded circuits; subclass 63 for long
cable systems; and subclass 69 for line-clearing and
circuit-maintenance systems.
307, Electrical Transmission or Interconnection Systems,
appropriate subclasses, particularly subclass 146 and 147+
for miscellaneous systems of distribution with transmission
lines usually of the electrically short type.
315, Electric Lamp and Discharge Devices: Systems, 3.5 and
4+ for transmission line sections structurally combined with
cathode-ray tubes; and subclasses 39+ for electronic tubes
which are structurally combined with a transmission line of
the distributed parameter type.
324, Electricity: Measuring and Testing, 51, 54, 66+, 95,
and 600+ for arrangements to determine the electrical
characteristics of transmission lines.
329, Demodulators, subclass 322 for a frequency demodulator
including distributed parameter structure and subclass 354
for an amplitude demodulator including distributed parameter
structure.
330, Amplifiers, 53 for amplifiers coupled to a long line.
340, Communications: Electrical, for miscellaneous
electrical signaling systems which include a long line. Note
310.01 for such systems where the signal is transmitted over
a power line; and subclass 320 for signaling using a fluid
conduit to transmit the signal.
343, Communications: Radio Wave Antennas, 700 for antennas
which may involve long lines.
379, Telephonic Communications, for telephone transmission
line systems; particularly 90.01 for composite systems
(e.g., telegraph and telephone); subclass 398 for
anti-inductive systems; and subclasses 1+ for long line
testing device.
Subclass:
237
Leaky lines:
This subclass is indented under subclass 236. Subject matter
wherein the long line carries a travelling wave which is
lightly coupled to a series of leakage apertures to create a
concentrated, uniform, radiation field in the immediate
vicinity of the aperture.
(1) Note. Many of the patents in this subclass are directed
towards radiating energy from a coaxial cable in a building,
tunnel, or mine and/or for vehicle communication.
SEE OR SEARCH CLASS:
343, Communications: Radio Wave Antennas, 700 for the
structural details of the radiating aperture used in
conjunction with the long line, e.g., subclasses 767+ for
slots.
Subclass:
238
Strip type:
This subclass is indented under subclass 236. Subject matter
wherein the long line is of the type having planar
conductors.
(1) Note. Examples of such lines are stripline, microstrip,
slot line, and coplanar waveguide.
Subclass:
239
Waveguide type:
This subclass is indented under subclass 236. Subject matter
particularly adapted for propagating electric waves having an
electric or magnetic field component extending in the
direction of propagation.
(1) Note. The waveguide may be a hollow dielectric or metal
tube or solid dielectric rod, the wave energy being
propagated along the interior of the tube or rod and confined
by the walls of the tube or rod.
Subclass:
240
Surface wave:
This subclass is indented under subclass 239. Subject matter
for propagating, without substantial radiation,
electromagnetic energy along the interface between two media
having different physical properties (e.g., different
permittivities).
(1) Note. While the electromagnetic field extends to
infinity in a direction transverse to the guide, the energy
density decreases with distance so that most of the energy
propagation is in the immediate neighborhood of the
interface.
(2) Note. Surface wave guiding structures may comprise
dielectric clad conductive cylinders, conductive planes with
parallel grooves or conductive cylinders with radial grooves,
or a dielectric rod clad with a dielectric media of a
different permittivity.
Subclass:
241
Flexible:
This subclass is indented under subclass 239. Subject matter
wherein the waveguide is articulated, segmented, or otherwise
structured so as to permit desired bending without
appreciable wave mode distortion and/or without appreciable
characteristic impedance variation.
Subclass:
242
Circular or helical structure:
This subclass is indented under subclass 239. Subject matter
wherein the guide structure is a hollow conductive cylinder,
a helical conductor, or a helical conductor located within a
conductive screen.
Subclass:
243
Shielded type:
This subclass is indented under subclass 236. Subject matter
wherein the long line comprises at least one electrical
conductor surrounded by an electrically conducting screen.
(1) Note. This subclass includes, for example, coaxial
cable-type conductors and other transmission lines having one
or more conductors surrounded by an outer metal sheath which
is designed for use as a conductor.
SEE OR SEARCH THIS CLASS, SUBCLASS:
12 for interference suppression and/or elimination systems
which may include electrical screens or shields, and for
conductor arrangements which involve shielding means or
structure in addition to the conductor arrangement.
SEE OR SEARCH CLASS:
174, Electricity: Conductors and Insulators, particularly 28
for the structure of coaxial or concentric-type cables
having a fluid or vacuum; subclass 36 for electrically
shielded or screened conductors; and subclasses 102+ for
cables or conductor structure having a conductive armor or
sheath.
315, Electric Lamp and Discharge Devices: Systems, 4 for
cathode-ray tubes which have structurally combined therewith
a coaxial cable section; and subclasses 39+ for other
electronic tubes which have structurally combined therewith a
coaxial cable section.
343, Communications: Radio Wave Antennas, 841 for antennas
with an electrical shield; subclass 851 for antennas with a
coupling network including a radiation suppressor; and
subclass 905 for antennas combined with a transmission line
which may include a shield for the transmission line.
Subclass:
244
Including spaced, electrically compensated, internal support
means:
This subclass is indented under subclass 243. Subject matter
having spaced apart support means for an internal conductor,
wherein the support means and/or ancillary reactance means
function to reduce the effects of impedance discontinuities
normally resulting from the use of a discontinuous support
structure.
Subclass:
245
LONG LINE ELEMENTS AND COMPONENTS:
This subclass is indented under the class definition.
Components and elements not constituting a complete network
which are limited by claimed structure to use in long lines
and which are not otherwise classified, and also long line
elements.
(1) Note. Included in this subclass are structures and
devices for modifying the characteristics of a transmission
line at a particular location, for example, line
short-circuiting switches, line-shorting plugs, impedance
elements, and long line elements which are terminated in
other than their characteristic impedance and are nonresonant
(e.g., a short-circuited line 1/8 of a wavelength long).
SEE OR SEARCH THIS CLASS, SUBCLASS:
13 for resonator type breakdown discharge device networks
for short circuiting a long line.
22 for dissipating terminations for long lines.
101 for branched circuits having switching means.
219 for resonators.
236 for long lines.
SEE OR SEARCH CLASS:
174, Electricity: Conductors and Insulators, appropriate
subclasses for conductors, housing insulators, conductor
joints, and end structure where no significant wave
propagation characteristic limiting the structures to use
with long lines is claimed.
200, Electricity: Circuit Makers and Breakers, appropriate
subclasses for switching structure in general.
285, Pipe Joints or Couplings, appropriate subclasses for
couplings for coaxial lines or for waveguides where no
significant electrical features are claimed.
329, Demodulators, subclass 322 for a frequency demodulator
including distributed parameter structure and subclass 354
for an amplitude demodulator including distributed parameter
structure.
330, Amplifiers, 53 for amplifiers with distributed
parameter coupling means including subject matter involving
structural details of such means.
343, Communications: Radio Wave, 907 for antenna
components.
439, Electrical Connectors, for transmission line electrical
connectors where no significant wave propagation
characteristic are claimed which limit the structure to use
with long lines.
Subclass:
246
Strip type:
This subclass is indented under subclass 245. Subject matter
wherein the long line is of the type having planar
conductors.
(1) Note. Examples of such lines are stripline (two ground
planes), microstrip (one ground plane), slot lines, or
coplanar waveguides.
SEE OR SEARCH THIS CLASS, SUBCLASS:
238 for strip-type lines, per se.
Subclass:
247
Semiconductor mounts:
This subclass is indented under subclass 246. Subject matter
wherein a strip-type board is used to hold or support a
solid-state device such as a transistor.
SEE OR SEARCH CLASS:
257, Active Solid-State Devices (e.g., Transistors,
Solid-State Diodes), subclasses 662-664.
Subclass:
248
Waveguide elements and components:
This subclass is indented under subclass 245. Components and
elements which are limited to use with waveguides, and also
waveguide elements.
(1) Note. A waveguide may be a hollow dielectric or metal
tube or a solid dielectric rod, the wave energy being
propagated along the interior of the tube or rod and confined
by the walls of the tube or rod.
SEE OR SEARCH THIS CLASS, SUBCLASS:
113 for directional couplers having parallel-guide
waveguides.
114 for directional couplers having crossed-guide
waveguides.
122 for hybrid-type networks using waveguide.
135 for frequency separation utilizing long line elements
including waveguide elements.
157 for delay lines including long line waveguide elements.
239 for types of waveguide.
SEE OR SEARCH CLASS:
138, Pipes and Tubular Conduits, subclasses 100-178 for
waveguide structures and accessories which are not limited to
electrical use.
174, Electricity: Conductors and Insulators, appropriate
subclasses for conduits and transmission line structure
limited to electrical use but not having long line
characteristics.
285, Pipe Joints or Couplings, appropriate subclasses for
pipe couplings not limited to electrical use.
329, Demodulators, subclass 322 for a frequency demodulator
including distributed parameter structure and subclass 354
for an amplitude demodulator including distributed parameter
structure.
343, Communications: Radio Wave Antennas, subclass 783 for
waveguide-type antennas with internal wave refraction means;
and subclass 785 for waveguide-type antennas which are of the
dielectric type.
Subclass:
249
Bend:
This subclass is indented under subclass 248. Subject matter
wherein the longitudinal axis of the waveguide element
changes direction.
Subclass:
250
Active element mounting:
This subclass is indented under subclass 248. Subject matter
wherein the waveguide element is designed to support an
active element (e.g., diode, tube) in the waveguide.
Subclass:
251
Mode suppressor:
This subclass is indented under subclass 248. Subject matter
wherein the waveguide is designed to pass a desired
electromagnetic mode or modes and block or filter out any
undesired electromagnetic mode or modes.
Subclass:
252
Window:
This subclass is indented under subclass 248. Subject matter
wherein the waveguide element contains an electromagnetic
wave-permeable solid plate lying transverse to the direction
of wave propagation.
Subclass:
253
Including variable impedance:
This subclass is indented under subclass 248. Subject matter
wherein structure is provided in the waveguide to adjust the
impedance (normally the reactive portion) of the line at
selected terminal planes.
(1) Note. Movable shorting stubs and movable irises are
classified here.
SEE OR SEARCH THIS CLASS, SUBCLASS:
33 for impedance matching between networks.
Subclass:
254
Connectors and interconnections:
This subclass is indented under subclass 248. Subject matter
having means for joining separate waveguide sections.
Subclass:
255
Quick disconnect:
This subclass is indented under subclass 254. Subject matter
wherein the joined waveguides are provided with means to
rapidly connect and disconnect the waveguides.
Subclass:
256
Movable:
This subclass is indented under subclass 254. Subject matter
including structure which allows relative movement between
the joined waveguides during normal operation.
Subclass:
257
In line:
This subclass is indented under subclass 256. Subject matter
wherein the axes of the joined waveguide sections are
aligned.
Subclass:
258
Switch:
This subclass is indented under subclass 248. Subject matter
wherein wave energy is selectively passed along the waveguide
by a means which abruptly connects and disconnects a single
waveguide input from a single waveguide output.
SEE OR SEARCH THIS CLASS, SUBCLASS:
101 for switches in branched circuits.
Subclass:
259
Mechanically movable:
This subclass is indented under subclass 258. Subject matter
wherein the connecting and disconnecting is accomplished
using mechanically actuated means.
(1) Note. The mechanically actuated means may be a movable
vane or movable shorting pins.
SEE OR SEARCH THIS CLASS, SUBCLASS:
105 for mechanical switches in branched circuits.
Subclass:
260
Connectors and interconnections:
This subclass is indented under subclass 245. Subject matter
having means for joining separate long line sections.
Subclass:
261
Rotary coupling:
This subclass is indented under subclass 260. Subject matter
having means to provide relative rotation between two
intercoupled long line sections.
Subclass:
262
Switch:
This subclass is indented under subclass 245. Subject matter
wherein energy is selectively passed along the long line by
abruptly connecting and disconnecting a single line input
from a single line output.
Subclass:
263
Including variable impedance:
This subclass is indented under subclass 245. Subject matter
wherein means are connected to the long line to adjust the
impedance (normally the reactive portion) of the line at
selected terminal planes.
(1) Note. Movable short circuits and variable reactances
are classified here.
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Last Modified: 6 October 2000