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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Electronic Products Branch)
Class 332
MODULATORS
Class Definition:
A. BASIC SUBJECT MATTER OF CLASS
This is the generic class for modulators. A modulator is a
device which varies a characteristic of a repetitious
electrical or electromagnetic wave of less than infrared
frequency in accordance with a characteristic of an
arbitrarily varying information carrying signal.
Classification herein is broadly by the type of modulation
exhibited by the output signal.
B. COMBINATIONS WITH BASIC SUBJECT MATTER INCLUDED IN THIS
CLASS
1. A modulator combined with structure for measuring or
indicating some aspect of the modulation process or
characteristic of the modulated signal is classified here.
Specifically, measurement or indication of a frequency or
amplitude modulator is classified here.
2. A modulator combined with a specific modulating signal
source (e.g., microphone or photocell) is classified here by
modulation type unless provided for elsewhere.
3. A modulator combined with structure to improve the
modulation is classified here. Such structure might include,
for example, a particular power supply for electronic devices
within the modulator or structure to correct for distortions
in the modulated wave.
4. A combination including both a modulator and a
demodulator is classified here where such combination is not
provided for elsewhere.
C. MISCELLANEOUS SYSTEMS AND DEVICES USED WITH MODULATORS
This class also provides for (1) miscellaneous systems and
devices which are not of general utility and which are
limited to use with modulators and (2) miscellaneous systems
and devices useful with modulators which are not otherwise
classified. Examples of such subject matter are a structure
limited in use to measurement of a modulated wave, a
multiplex modulator where a plurality of modulating signals
are imposed on a carrier or pulse wave, or a modulation
converter where modulated energy of one character is
converted to modulation energy of a different character
(e.g., frequency modulation to amplitude modulation).
LINES WITH OTHER CLASSES AND WITHIN THIS CLASS
Excluded from this class are light wave modulators which are
classified elsewhere. (See References to Other Classes,
below. )
Excluded from this class are pulse code modulators and delta
modulators which are now classified elsewhere. (See
References to Other Classes, below. )
Excluded from this class are those devices comprising an
oscillator combined with or including a specific element
which is merely responsive to an external physical condition
(e.g., ambient temperature) and which thereby varies a
parameter (e.g., amplitude or frequency) of the oscillator.
Such devices are classified elsewhere. (See References to
Other Classes, below.) However an oscillator in combination
with significant modulating structure is classified in Class
332.
Classes 330 Amplifiers and 331 Oscillators contain subject
matter directed to subcombinations potentially usable in
modulators (e.g., an electrical amplifier combined with
suitable gain control structure could be utilized as an
amplitude modulator). Therefore, these classes should be
considered in completing the search for subject matter of
Class 332. See the related SEARCH CLASS notes in References
to Other Classes, below.
Many classes contain subject matter which includes modulators
or devices analogous to modulators as subcombinations
thereof. Thus, as appropriate, combination classes listed
below in the SEARCH CLASS notes in References to Other
Classes, below, should be considered in completing the search
of subject matter relevant to Class 332.
See the Glossary, below, for nonelectrical modulators.
MODULATORS OF NONELECTRICAL TYPE
The term modulator has a variety of meanings outside of the
electrical art. Foremost among these are fluid control
devices and optical control devices. Examples of fluid
control type modulators and optical type modulators can be
found in References to Other Classes, below.
Other diverse types of nonelectrical modulators can be found
in References to Other Classes, below.
SEE OR SEARCH THIS CLASS, SUBCLASS:
118 for measuring in a frequency modulator.
150 for measuring in an amplitude modulator.
REFERENCES TO OTHER CLASSES
SEE OR SEARCH CLASS:
60, Power Plants, appropriate subclasses for fluid control
type modulators.
62, Refrigeration; appropriate subclasses for fluid control
type modulators.
73, Measuring and Testing, appropriate subclasses for
measuring or testing of a parameter which is typically
neither electrical, optical, thermal, nor chemical and which
may include a modulation technique.
137, Fluid Handling; appropriate subclasses for fluid
control type modulators.
178, Telegraphy, 66.1 for a teles:graphic system which
transmits messages between stations using alternating or
pulsating currents and particularly subclass 66.2 for such a
system having a transmitter which is turned on and off.
180, Motor Vehicles, appropriate subclasses for fluid control
type modulators.
250, Radiant Energy, 200 for a photocell-controlled
modulator combined with a significant optical system for
controlling the light intensity on the photocell, subclass
250 for radio and microwave wavemeters and frequency
measurement systems for radio waves, subclass 263 for an
electrical wave modulated by signals emitted from a radiation
detector in or about a well, and subclasses 336.1+ for
structure comparable to that of subclasses 200+ described
above wherein the photocell is responsive to invisible
radiant energy.
257, Active Solid-State Devices (e.g., Transistors,
Solid-State Diodes), appropriate subclasses for active
semiconductor devices, per se.
264, Plastic and Nonmetallic Article Shaping or Treating:
Processes, appropriate subclasses for diverse types of
nonelectrical modulators.
303, Fluid-Pressure and Analogous Brake System, appropriate
subclasses for fluid control type modulators.
307, Electrical Transmission or Interconnection Systems,
subclass 3 for systems superimposing currents of diverse
frequency or phase, subclass 73 for plural supply circuits or
sources of diverse frequency, and subclasses 106+ for
waveform or wave shape determinative or pulse producing
systems which are class appropriate.
313, Electric Lamp and Discharge Devices, appropriate
subclasses for the structure of electronic tubes.
315, Electrical Lamp and Discharge Devices: Systems, 3 for a
combination of cathode-ray tube with ray control structure
which may utilize a modulation technique, subclass 39.3 for a
travelling wave tube with delay line and subclasses 39.51+
for a magnetron combined with diverse circuit element.
318, Electricity: Motive Power Systems, subclass 599 for
pulse width modulated power control of a servo motor,
subclasses 606+ for servo systems utilizing a feedback signal
which frequency or phase modulates a system carrier, subclass
684 for a particular modulator structure used in servomotor
control, and subclass 811 for pulse width modulated time
control of a pulse train supplied to the primary winding of
an induction motor.
323, Electricity: Power Supply or Regulation Systems,
appropriate subclasses for control of the magnitude or phase
of current or voltage in a system comprising a single
electrical source coupled to a single electrical load.
324, Electricity: Measuring and Testing, appropriate
subclasses for measurement of electrical properties, in
general, and particularly 76.39 for frequency measurement of
electrical waves, subclasses 76.77+ for measurement of the
phase relationship between electrical waves, and subclass 118
for modulation of voltage or current to be measured onto a
carrier combined with subsequent structure to recover a
replica of the original voltage or current by demodulation.
327, Miscellaneous Active Electrical Nonlinear Devices,
Circuits, and Systems, particularly 113 for miscellaneous
frequency control, subclasses 291+ for miscellaneous clock or
pulse waveform generating, subclasses 231+ for phase shift by
less than the period of an input signal, and subclasses 306+
for miscellaneous amplitude control.
329, Demodulators, appropriate subclasses for demodulators,
per se.
330, Amplifiers, subclass 10, for an amplifier having an
input which is the output of a modulator and an output which
is the input of a subsequent demodulator, and subclasses
127+, 144+ and 250+ for an amplifier with gain control
structure.
331, Oscillators, 1 for automatic frequency stabilization of
an oscillator and indented thereunder subclasses 23+ for
achieving this stabilization through a modulation technique,
subclasses 37+ for two nonarbitrary sources of slightly
different frequencies and substantially equal amplitudes
which are combined to produce the respective sum or
difference frequencies, subclasses 46+ for plural oscillator
systems in general, subclass 58 for an oscillator with
structure to perform an additional simultaneous function,
subclasses 65+ for an oscillator responsive to an external
condition, subclass 83 for a klystron type oscillator,
subclasses 86+ for a magnetron type oscillator, subclass 106
for an oscillator with repetitive amplitude variation,
subclasses 177+ for an oscillator combined with frequency
adjustment, and subclasses 182+ for amplitude stabilization
or control in an oscillator.
333, Wave Transmission Lines and Networks, subclass 20 for
passive networks which modify the amplitude-time
characteristic of waves passing therethrough, and subclasses
219+ for resonators in general.
340, Communications: Electrical, 870.01 for telemetry
systems and especially subclasses 870.18+ indented thereunder
for such systems where the quantity to be telemetered is
imposed on a carrier by a particular type of modulation.
341, Coded Data Generation or Conversion, 126 for a pulse
code modulator, per se, and subclass 143 for a delta
modulator, per se.
342, Communications: Directive Radio Wave Systems and
Devices (e.g., Radar, Radio Navigation), appropriate
subclasses for radar systems or subsystems utilizing devices
(i.e., radar modulators) which vary the amplitude, frequency
or phase of a radar signal in a nonarbitrary manner.
348, Television, subclass 472 for individual television
signals combined into a specific transmission format by a
pulse code modulated technique, subclass 642 for a natural
color television signal generator including a modulator
particularly adapted for use therein, and subclass 724 for a
modulator using in television transmitter circuitry.
358, Facsimile and Static Presentation Processing, subclass
469 for facsimile circuitry including a modulator
particularly adapted for use therein.
359, Optics; Systems (Including Communication and Elements),
237 for light wave modulators; appropriate subclasses for
optical type modulators.
360, Dynamic Magnetic Information Storage or Retrieval, 29
for modulators of particular utility in dynamic magnetic
recording or reproducing.
363, Electric Power Conversion Systems, subclass 26 for a
DC-AC inverter having pulse width modulated automatic control
of output current or voltage, and subclasses 41+ for a DC-AC
inverter using a pulse modulation technique to introduce or
eliminate frequency components.
367, Communications, Electrical: Acoustic Wave System and
Devices, appropriate subclasses for diverse types of
nonelectrical modulators.
369, Dynamic Information Storage or Retrieval, subclass 8
for a radio combined with an information retrieval device
wherein an oscillator is controlled by a retrieved
information signal, subclass 61 for direct storage or
retrieval of a modulated carrier signal, subclass 62 for
storage or retrieval involving a modulated signal wherein the
carrier is partially or completely suppressed prior to
storage and reinserted subsequent to retrieval, subclass 90
for storage of a quadraphonic signal utilizing modulation of
an AC wave by at least one of the respective channels, and
subclasses 127+ for mechanical modification or sensing of a
storage medium which may utilize a modulation technique.
370, Multiplex Communications, appropriate subclasses which
may have particular details of modulation techniques.
372, Coherent Light Generators, for optical type modulators.
374, Thermal Measuring and Testing, appropriate subclasses
for measurement systems responsive to an external thermal
condition which may utilize a modulation technique.
375, Pulse or Digital Communications, appropriate subclasses
for subject matter of this class combined with transmitting
structure to couple a modulated pulse wave to a transmission
medium and subclass 237 and 242+ for a digital communication
transmitter or system utilizing pulse number modulation or
pulse code modulation, respectively.
379, Telephonic Communications, 64 for a telephone speech
signal transmitter utilizing a carrier modulation technique,
and subclasses 93+ (particularly subclass 98) for
transmission of a digital message signal over a telephone
line which may utilize a modulation technique.
380, Cryptography, for all electrical communications
equipment which process an information signal for purposes of
concealment and particularly 10 for scrambling of a video
signal using a modulation related technique, subclasses 31+
for cryptos:graphic electrical signal modification using a
plural modulation technique, and subclass 35 for
cryptos:graphic signal modification using a variable time
delay modulation technique.
381, Electrical Audio Signal Processing Systems and Devices,
3 for audio systems or devices which process a stereo signal
which is transmitted in a frequency-only modulated format,
subclasses 15+ for audio systems or devices which process a
stereo signal which is transmitted in an amplitude modulated
or both an AM and angle modulated format, and subclass 316
for control of the output amplitude of a hearing aid as a
function of frequency.
386, Television Signal Processing for Dynamic Recording or
Reproducing, 26 for processing of a natural color television
signal including frequency in modulation for recording on the
same track.
430, Radiation Imagery Chemistry: Process, Composition, or
Product Thereof, appropriate subclasses for diverse types of
nonelectrical modulators.
432, Heating, appropriate subclasses for diverse types of
nonelectrical modulators.
455, Telecommunications, appropriate subclasses for subject
matter of this class combined with transmitting structure to
couple the modulated carrier wave to a transmission medium.
GLOSSARY:
ARBITRARILY VARYING
Indicates having a future value which is not predictable from
past values. (Arbitrary is the opposite of repetitious).
CARRIER
Is an electrical or electromagnetic repetitious sinusoidal
wave.
CHARACTERISTIC
Is an attribute associated with the size or shape of a wave
or signal. Examples are amplitude, frequency, or phase of a
sine wave and repetition rate, position, amplitude or width
of a nonsine wave.
MODULATING SIGNAL
Is an information carrying signal whose informational content
is to be impressed on a carrier or pulse wave.
MODULATOR
Is a device which varies a characteristic of a repetitious
electrical or electromagnetic wave of less than infrared
frequency in accordance with a characteristic of an
arbitrarily varying modulating signal.
PULSE WAVE
Is an electrical or electromagnetic repetitious nonsinusoidal
wave. Examples are square wave, saw-tooth wave, or
trapezoidal wave.
REPETITIOUS WAVE
Is a cyclic wave whose individual component cycles are
substantially identical. Examples of repetitious waves are
sine waves, square waves, saw-tooth waves, and trapezoidal
waves.
SUBCLASSES
Subclass:
100
FREQUENCY SHIFT KEYING MODULATOR OR MINIMUM SHIFT KEYING
MODULATOR:
This subclass is indented under the class definition.
Subject matter in which the frequency of the carrier is
shifted among a plurality of discrete values in accordance
with the modulating signal.
(1) Note. This subclass and its indents provide for a
minimum shift keying (MSK) modulator which is a frequency
shift keying modulator having phase continuity at the
frequency transition points.
(2) Note. This subclass includes frequency shift keying
modulators, per se. See the SEARCH CLASS notes below for
combinations with the subject matter of this subclass.
SEE OR SEARCH THIS CLASS, SUBCLASS:
103 for a phase shift keying modulator.
SEE OR SEARCH CLASS:
375, Pulse or Digital Communications, 272 for a frequency
shift keying system (i.e., transmitter and receiver), and
subclasses 303+ for a frequency shift keying modulator
combined with transmitting structure.
Subclass:
101
Including logic element (e.g., logic gate or flip-flop):
This subclass is indented under subclass 100. Subject matter
containing a component which performs a Boolean Algebraic
operation.
(1) Note. Such components may be combinational or
sequential (e.g., AND gates, OR gates or J-K flip-flops).
Subclass:
102
Including discrete semiconductor device:
This subclass is indented under subclass 100. Subject matter
containing an electrical device whose constituent portions
are constructed from solid material having room temperature
conductivity between that of a conductor and an insulator and
which conductivity is typically modified through the addition
of small amounts of dopant.
(1) Note. This might include, for example, semiconductor
diodes or transistors of diverse type.
Subclass:
103
PHASE SHIFT KEYING MODULATOR OR QUADRATURE AMPLITUDE
MODULATOR:
This subclass is indented under the class definition.
Subject matter in which the phase of the carrier is shifted
among a plurality of discrete angles in accordance with the
modulating signal.
(1) Note. Also included here is the case where the phase
and amplitude of the carrier are simultaneously shifted among
a plurality of discrete angle/magnitude pairs (i.e., QAM).
(2) Note. This subclass includes phase shift keying
modulators, or quadrature amplitude modulators, per se. See
the SEARCH CLASS notes below for combinations with the
subject matter of this subclass.
SEE OR SEARCH THIS CLASS, SUBCLASS:
100 for a frequency shift keying modulator.
SEE OR SEARCH CLASS:
375, Pulse or Digital Communications, subclass 261 for a
quadrature amplitude modulation system (i.e., transmitter and
receiver), subclasses 279+ for a phase shift keying system,
and subclass 308 for a phase shift keying modulator combined
with transmitting structure.
Subclass:
104
Including logic element (e.g., logic gate or flip-flop):
This subclass is indented under subclass 103. Subject matter
containing a component which performs a Boolean Algebraic
operation.
(1) Note. Such components may be combinational or
sequential (e.g., AND gates, OR gates or J-K flip-flops).
Subclass:
105
Including discrete semiconductor device:
This subclass is indented under subclass 103. Subject matter
containing an electrical device whose constituent portions
are constructed from solid material having room temperature
conductivity between that of a conductor and an insulator and
which conductivity is typically modified through the addition
of small amounts of dopant.
(1) Note. This might include, for example, semiconductor
diodes or transistors of diverse type.
Subclass:
106
PULSE OR INTERRUPTED CONTINUOUS WAVE MODULATOR:
This subclass is indented under the class definition.
Subject matter producing a final output signal consisting of
a repetitious pulse wave or a pulsed continuous wave having
one or more of its characteristics varied in accordance with
one or more modulating signals.
(1) Note. Examples of pulse waves are square waves,
sawtooth waves, and trapezoidal waves.
(2) Note. If a system includes a pulse modulator, but the
final output signal is a frequency, phase or an amplitude
modulated wave, the modulator is classified in subclasses
117+, 144+ or 149+, respectively.
(3) Note. Systems having a final output that is pulse code
modulated (PCM) or delta modulated are found in Class 341
subclasses 126+ or 143.
(4) Note. This subclass includes pulse modulators, per se.
See the SEARCH CLASS notes below for combinations with the
subject matter of this subclass.
SEE OR SEARCH THIS CLASS, SUBCLASS:
117 for a frequency modulator.
144 for a phase modulator.
149 for an amplitude modulator.
SEE OR SEARCH CLASS:
375, Pulse or Digital Communications, appropriate subclasses,
for combinations of a pulse modulator with transmitting
structure.
Subclass:
107
Including stabilization or alternatively distortion, noise or
other interference prevention, reduction, or compensation:
This subclass is indented under subclass 106. Subject matter
including the neutralization of an undesirable characteristic
of a pulse modulator or its signals.
(1) Note. Distortion may be introduced to the pulse
modulating system in order to compensate for other inherent
distortion.
(2) Note. The neutralized characteristic might be some form
of system instability.
SEE OR SEARCH THIS CLASS, SUBCLASS:
123 for distortion or noise control in a frequency
modulator.
159 for distortion or noise control in an amplitude
modulator.
SEE OR SEARCH CLASS:
375, Pulse or Digital Communications, subclass 254, 285 and
296 for noise or distortion control in a system or
transmitter.
Subclass:
108
Plural modulation:
This subclass is indented under subclass 106. Subject matter
having a plurality of modulators, modulating signals, or
diverse output modulation types simultaneously present or
individually selectable.
(1) Note. At least one final output signal must be a pulse
modulated signal for classification herein.
(2) Note. Multiplex pulse modulators, per se, are
classified here.
SEE OR SEARCH THIS CLASS, SUBCLASS:
119 for plural modulation in a frequency modulator.
145 for plural modulation in a phase modulator.
151 for plural modulation in an amplitude modulator.
SEE OR SEARCH CLASS:
370, Multiplex Communications, appropriate subclasses and
particularly subclass 205 for combined pulse width and pulse
position modulation, subclass 212 for a multiplex transmitter
using pulse width modulation and subclass 213 for multiplex
transmitter using pulse position modulation.
Subclass:
109
Pulse width modulator:
This subclass is indented under subclass 106. Subject matter
producing a pulse wave output signal in which the pulse width
(duration) is varied by the modulating signal.
SEE OR SEARCH CLASS:
375, Pulse or Digital Communications, subclass 238 for a
combination of pulse width modulator with transmitting
structure.
Subclass:
110
Including discrete semiconductor device having three or more
electrodes:
This subclass is indented under subclass 109. Subject matter
utilizing a device with three external connection points
where the constituent portions of the device are constructed
from solid material having room temperature conductivity
between that of a conductor and an insulator and which
conductivity is typically modified through the addition of
small amounts of dopant.
(1) Note. This might include, for example, semiconductor
diodes or transistors of diverse type.
Subclass:
111
Including electron discharge device:
This subclass is indented under subclass 109. Subject matter
utilizing a device which has electrical current flow between
two spaced electrodes in a gas, vapor or vacuum.
(1) Note. This might include, for example, vacuum or gas
tubes such as diodes, triodes or pentodes.
(2) Note. Additional control electrodes may be present.
Subclass:
112
Pulse position, frequency, phase or spacing modulator:
This subclass is indented under subclass 106. Subject matter
producing a pulse wave output signal in which the relative
positions of the pulses, the frequency (repetition rate) of
the pulses, the phase of the pulses, or the spacing (time)
between the pulses is varied by the modulating signal.
SEE OR SEARCH CLASS:
375, Pulse or Digital Communications, subclass 239 for a
combination of pulse position, frequency or spacing modulator
with transmitting structure.
Subclass:
113
Including discrete semiconductor device having three or more
electrodes:
This subclass is indented under subclass 112. Subject matter
utilizing a device with three external connection points
where the constituent portions of the device are constructed
from solid material having room temperature conductivity
between that of a conductor and an insulator and which
conductivity is typically modified through the addition of
small amounts of dopant.
(1) Note. This might include, for example, semiconductor
diodes or transistors of diverse type.
Subclass:
114
Including electron discharge device:
This subclass is indented under subclass 112. Subject matter
utilizing a device which has electrical current flow between
two spaced electrodes in a gas, vapor or vacuum.
(1) Note. This might include, for example, vacuum or gas
tubes such as diodes, triodes or pentodes.
(2) Note. Additional control electrodes may be present.
Subclass:
115
Pulse amplitude modulator:
This subclass is indented under subclass 106. Subject matter
producing a pulse wave output signal in which the amplitude
of the pulses is controlled by the modulating signal.
SEE OR SEARCH CLASS:
375, Pulse or Digital Communications, 300 for a combination
of pulse amplitude modulator with transmitting structure, and
subclasses 268+ for a pulse amplitude modulation system
(i.e., transmitter and receiver).
Subclass:
116
Including discrete semiconductor device having three or more
electrodes:
This subclass is indented under subclass 115. Subject matter
utilizing a device with three external connection points
where the constituent portions of the device are constructed
from solid material having room temperature conductivity
between that of a conductor and an insulator and which
conductivity is typically modified through the addition of
small amounts of dopant.
(1) Note. This might include, for example, semiconductor
diodes or transistors of diverse type.
Subclass:
117
FREQUENCY MODULATOR:
This subclass is indented under the class definition.
Subject matter in which the frequency of the carrier is
varied over a continuum of values in accordance with the
modulating signal.
(1) Note. This subclass includes frequency modulators, per
se. See the SEARCH CLASS notes below for combinations with
the subject matter of this subclass.
SEE OR SEARCH THIS CLASS, SUBCLASS:
106 for a pulse modulator.
144 for a phase modulator.
149 for an amplitude modulator.
SEE OR SEARCH CLASS:
455, Telecommunications, 42 for frequency modulation in a
system with separated transmitter and receiver, and
subclasses 110+ for a combination of frequency modulator with
transmitting structure.
Subclass:
118
Including measuring or indicating:
This subclass is indented under subclass 117. Subject matter
combined with apparatus producing a qualitative or
quantitative output representative of a characteristic of the
modulator or its signals.
SEE OR SEARCH THIS CLASS, SUBCLASS:
150 for measuring in an amplitude modulator.
SEE OR SEARCH CLASS:
331, Oscillators, subclass 64 for an oscillator with
indicator.
455, Telecommunications, 67.1, for measuring or testing in a
system with separated transmitter and receiver and subclass
115 for measuring or testing of a telecommunications
tramsmitter.
Subclass:
119
Plural modulation:
This subclass is indented under subclass 117. Subject matter
having a plurality of modulators, modulating signals, or
diverse output modulation types simultaneously present or
individually selectable.
(1) Note. At least one final output signal must be a
frequency modulated signal.
(2) Note. Multiplex frequency modulators, per se, are
classified here.
SEE OR SEARCH THIS CLASS, SUBCLASS:
108 for plural modulation in a pulse modulator.
145 for plural modulation in a phase modulator.
151 for plural modulation in an amplitude modulator.
SEE OR SEARCH CLASS:
370, Multiplex Communications, appropriate subclasses and
particularly 204 for plural diverse modulation techniques,
subclass 215 for multiplex transmitter using phase modulation
and subclass 483 for a multiplex transmitter using frequency
modulation.
455, Telecommunications, subclass 61 for plural modulation
where a single message is conveyed between a separated
transmitter and receiver and subclass 102 for plural
modulation in a telecommunications transmitter.
Subclass:
120
Including amplitude modulation:
This subclass is indented under subclass 119. Subject matter
in which at least one modulator is an amplitude modulator or
in which amplitude modulation is produced in addition to the
frequency modulation.
SEE OR SEARCH THIS CLASS, SUBCLASS:
145 for a phase modulator which includes an amplitude
modulator.
Subclass:
121
Including electron discharge device:
This subclass is indented under subclass 120. Subject matter
utilizing a device which has electrical current flow between
two spaced electrodes in a gas, vapor or vacuum.
(1) Note. This might include, for example, vacuum or gas
tubes such as diodes, triodes or pentodes.
(2) Note. Additional control electrodes may be present.
Subclass:
122
Including electron discharge device:
This subclass is indented under subclass 119. Subject matter
utilizing a device which has electrical current flow between
two spaced electrodes in a gas, vapor or vacuum.
(1) Note. This might include, for example, vacuum or gas
tubes such as diodes, triodes or pentodes.
(2) Note. Additional control electrodes may be present.
Subclass:
123
Including stabilization or alternatively distortion, noise or
other interference prevention, reduction or compensation:
This subclass is indented under subclass 117. Subject matter
including the neutralization of an undesirable characteristic
of a frequency modulator or its signals.
(1) Note. In some instances, distortion may be introduced
to the FM system in order to compensate for other inherent
distortion.
(2) Note. The neutralized characteristic might be some form
of system instability.
SEE OR SEARCH THIS CLASS, SUBCLASS:
107 for distortion or noise control in a pulse modulator.
159 for distortion or noise control in an amplitude
modulator.
SEE OR SEARCH CLASS:
455, Telecommunications, 63 and 501+ for noise control in a
telecommunication system with separated transmitter and
receiver and subclass 114 for harmonic radiation control in a
transmitter.
Subclass:
124
Nonlinearity reduction or compensation:
This subclass is indented under subclass 123. Subject matter
which diminishes the undesired effects of a modulator element
or circuit whose output is not directly proportional to its
input.
Subclass:
125
Automatic amplitude stabilization or control:
This subclass is indented under subclass 123. Subject matter
where undesired signal amplitude variations are controlled
without human intervention.
(1) Note. This might include, for example, suppression of
undesired amplitude modulation.
SEE OR SEARCH THIS CLASS, SUBCLASS:
155 for amplitude control in an amplitude modulator.
SEE OR SEARCH CLASS:
455, Telecommunications, subclass 116 for control of carrier
amplitude in a transmitter.
Subclass:
126
Automatic frequency stabilization or control:
This subclass is indented under subclass 123. Subject matter
in which undesired signal frequency variations are controlled
without human intervention.
(1) Note. Often the frequency being controlled is that of
the unmodulated carrier.
SEE OR SEARCH THIS CLASS, SUBCLASS:
161 for frequency control in an amplitude modulator.
SEE OR SEARCH CLASS:
331, Oscillators, 1 for automatic frequency control of an
oscillator.
455, Telecommunications, 75 for frequency stabilization in a
transceiver, subclass 113 for frequency control of a
frequency modulated transmitter and subclass 119 for
stabilizing the carrier frequency in a telecommunications
transmitter.
Subclass:
127
Phase or frequency locked loop:
This subclass is indented under subclass 126. Subject matter
in which a stable frequency is attained by utilizing a phase
or frequency locked loop.
Subclass:
128
Modulating signal applied to plural elements of the loop:
This subclass is indented under subclass 127. Subject matter
in which the modulating signal is injected into a plurality
of points within the locked loop.
Subclass:
129
Including microwave or distributed parameter structure:
This subclass is indented under subclass 117. Subject matter
utilizing a structure or device which is peculiar to
microwave frequencies or which has resistance, inductance or
capacitance not concentrated in lumped circuit elements.
SEE OR SEARCH THIS CLASS, SUBCLASS:
163 for similar structure in an amplitude modulator.
SEE OR SEARCH CLASS:
455, Telecommunications, subclass 111, for distributed
parameter structure in a frequency modulated transmitter.
Subclass:
130
With discrete semiconductor device:
This subclass is indented under subclass 129. Subject matter
containing an electrical device whose constituent portions
are constructed from solid material having room temperature
conductivity between that of a conductor and an insulator and
which conductivity is typically modified through the addition
of small amounts of dopant.
(1) Note. This might include, for example, semiconductor
diodes or transistors of diverse type.
Subclass:
131
With electron discharge device:
This subclass is indented under subclass 129. Subject matter
combined with a device which has electrical current flow
between two spaced electrodes in a gas, vapor or vacuum.
(1) Note. This might include, for example, vacuum or gas
tubes such as diodes, triodes or pentodes.
(2) Note. Additional control electrodes may be present.
Subclass:
132
Magnetron type:
This subclass is indented under subclass 131. Subject matter
in which an electron beam within the discharge device is
subject to a magnetic field.
SEE OR SEARCH CLASS:
315, Electric Lamp and Discharge Devices: Systems, subclass
5.13 and 39.51+ for a magnetron combined with diverse
circuit element.
331, Oscillators, subclass 5 for automatic frequency control
of a magnetron oscillator and subclasses 86+ for a magnetron
oscillator, per se.
Subclass:
133
Klystron type:
This subclass is indented under subclass 131. Subject matter
where the discharge device includes structure to vary the
relative velocity of different longitudinal portions of the
electron beam resulting in electron bunching.
SEE OR SEARCH CLASS:
315, Electric Lamp and Discharge Devices: Systems, 5 for a
cathode- ray tube circuit where the ray traverses a hollow
distributed parameter device and particularly indented
thereunder subclasses 5.21+, 5.46+ and 5.53+ for tuning
thereof.
331, Oscillators, 6 for automatic frequency control in a
klystron oscillator and subclass 83 for a klystron
oscillator, per se.
Subclass:
134
Travelling wave type:
This subclass is indented under subclass 131. Subject matter
wherein the discharge device has structure to slow a
travelling electromagnetic wave to more closely match the
velocity of an electron beam with which it is interacting.
SEE OR SEARCH CLASS:
315, Electric Lamp and Discharge Devices: Systems, 3.5 for
travelling wave tube combined with a delay transmission
line.
331, Oscillators, subclass 82 for a travelling wave-tube
type oscillator.
Subclass:
135
Including discrete semiconductor device:
This subclass is indented under subclass 117. Subject matter
containing an electrical device whose constituent portions
are constructed from solid material having room temperature
conductivity between that of a conductor and an insulator and
which conductivity is typically modified through the addition
of small amounts of dopant.
(1) Note. This might include, for example, semiconductor
diodes or transistors of diverse type.
Subclass:
136
With varactor:
This subclass is indented under subclass 135. Subject matter
in combination with a variable capacitance diode.
SEE OR SEARCH CLASS:
257, Active Solid-State Devices (e.g., Transistors,
Solid-State Diodes), subclass 312, 480, and 595-602 for
voltage variable capacitive type active semiconductor
devices.
Subclass:
137
Including electron discharge device:
This subclass is indented under subclass 117. Subject matter
utilizing a device which has electrical current flow between
two spaced electrodes in a gas, vapor or vacuum.
(1) Note. This might include, for example, vacuum or gas
tubes such as diodes, triodes or pentodes.
(2) Note. Additional control electrodes may be present.
Subclass:
138
Particular oscillator circuit:
This subclass is indented under subclass 137. Subject matter
including details of an associated frequency source.
(1) Note. Mere mention of an oscillator exclusive of detail
is insufficient for classification herein.
SEE OR SEARCH CLASS:
331, Oscillators, appropriate subclasses, for an oscillator,
per se.
Subclass:
139
Crystal oscillator type:
This subclass is indented under subclass 138. Subject matter
in which frequency generation is controlled by a crystal
resonator such as a piezoelectric crystal.
SEE OR SEARCH CLASS:
331, Oscillators, subclass 73, 116, 139, and 154+ for
piezoelectric-type oscillators.
Subclass:
140
With separate modulator tube (e.g., reactance tube):
This subclass is indented under subclass 139. Subject matter
where an electron discharge device distinct from the crystal
oscillator performs the actual modulation.
Subclass:
141
L-C oscillator type:
This subclass is indented under subclass 138. Subject matter
in which frequency generation is accomplished by an
inductive-capacitive network.
Subclass:
142
With separate modulator tube (e.g., reactance tube):
This subclass is indented under subclass 141. Subject matter
where an electron discharge device distinct from the L-C
oscillator performs the actual modulation.
Subclass:
143
Plural Modulator Tubes:
This subclass is indented under subclass 142. Subject matter
having a plurality of such distinct modulator tubes.
Subclass:
144
PHASE MODULATOR:
This subclass is indented under the class definition.
Subject matter in which the phase of the carrier is varied
over a continuum of values in accordance with the modulating
signal.
(1) Note. This subclass includes phase modulators, per se.
See SEARCH CLASS notes below for combinations with the
subject matter of this subclass.
SEE OR SEARCH THIS CLASS, SUBCLASS:
106 for a pulse modulator.
117 for a frequency modulator.
149 for an amplitude modulator.
SEE OR SEARCH CLASS:
455, Telecommunications, 42 for phase modulation in a system
with separated transmitter and receiver, and subclasses 110+
for a combination of a phase modulator with transmitting
structure.
Subclass:
145
Including amplitude modulator:
This subclass is indented under subclass 144. Subject matter
in which at least one modulator is an amplitude modulator or
in which amplitude modulation is produced in addition to
phase modulation.
SEE OR SEARCH THIS CLASS, SUBCLASS:
108 for plural modulation in a pulse modulator.
119 for plural modulation in a frequency modulator.
151 for plural modulation in an amplitude modulator.
SEE OR SEARCH CLASS:
370, Multiplex Communications, appropriate subclasses and
particularly 204 for plural diverse modulation techniques,
subclass 215 for a multiplexer using phase modulation,
subclass 483 for a multiplexer using frequency modulation,
subclass 533 for a multiplexer using pulse amplitude
modulation.
455, Telecommunications, subclass 61 for plural modulation
where a single message is conveyed between a separated
transmitter and receiver and subclass 102 for plural
modulation in a telecommunications transmitter.
Subclass:
146
Including discrete semiconductor device:
This subclass is indented under subclass 144. Subject matter
containing an electrical device whose constituent portions
are constructed from solid material having room temperature
conductivity between that of a conductor and an insulator and
which conductivity is typically modified through the addition
of small amounts of dopant.
(1) Note. This might include, for example, semiconductor
diodes or transistors of diverse type.
Subclass:
147
Including electron discharge device:
This subclass is indented under subclass 144. Subject matter
utilizing a device which has electrical current flow between
two spaced electrodes in a gas, vapor or vacuum.
(1) Note. This might include, for example, vacuum or gas
tubes such as diodes, triodes or pentodes.
(2) Note. Additional control electrodes may be present.
Subclass:
148
Push-pull circuit:
This subclass is indented under subclass 147. Subject matter
wherein there are two electrical paths with common output
each of which contains an electron discharge device and in
which the respective voltages are 180o out of phase with
respect to the other.
Subclass:
149
AMPLITUDE MODULATOR:
This subclass is indented under the class definition.
Subject matter in which the amplitude of the carrier is
varied over a continuum of values in accordance with the
modulating signal.
(1) Note. If a system includes an amplitude modulator, but
the final output signal is a pulse modulated, frequency
modulated or phase modulated wave, the modulator is
classified in subclasses 106+, 117+ or 144+, respectively.
(2) Note. This subclass includes amplitude modulators, per
se. See the SEARCH CLASS notes below for combinations with
the subject matter of this subclass.
SEE OR SEARCH THIS CLASS, SUBCLASS:
106 for a pulse modulator.
117 for a frequency modulator.
144 for a phase modulator.
SEE OR SEARCH CLASS:
455, Telecommunications, 108, for amplitude modulation in a
telecommunications transmitter.
Subclass:
150
Including measuring or indicating:
This subclass is indented under subclass 149. Subject matter
combined with apparatus producing a qualitative or
quantitative output representative of a characteristic of the
modulator or its signals.
SEE OR SEARCH THIS CLASS, SUBCLASS:
118 for measuring in a frequency modulator.
SEE OR SEARCH CLASS:
331, Oscillators, subclass 64 for an oscillator with
indicator.
455, Telecommunications, 67.1, for measuring or testing in a
system with separated transmitter and receiver and subclass
115 for measuring or testing of a telecommunications
transmitter.
Subclass:
151
Plural modulation:
This subclass is indented under subclass 149. Subject matter
having a plurality of modulators, modulating signals, or
diverse output modulation types simultaneously present or
individually selectable.
(1) Note. At least one final output signal must be an
amplitude modulated carrier wave.
(2) Note. Multiplex amplitude modulators, per se, are
classified here.
SEE OR SEARCH THIS CLASS, SUBCLASS:
108 for plural modulation in a pulse modulator.
119 for plural modulation in a frequency modulator.
145 for plural modulation in a phase modulator.
SEE OR SEARCH CLASS:
370, Multiplex Communications, appropriate subclasses and
particularly 204 for plural diverse modulation techniques,
and subclass 533 for a multiplexer using pulse amplitude
modulation.
455, Telecommunications, subclass 61 for plural modulation
where a single message is conveyed between a separated
transmitter and receiver and subclass 102 for plural
modulation in a telecommunications transmitter.
Subclass:
152
Including discrete semiconductor device:
This subclass is indented under subclass 151. Subject matter
containing an electrical device whose constituent portions
are constructed from solid material having room temperature
conductivity between that of a conductor and an insulator and
which conductivity is typically modified through the addition
of small amounts of dopant.
(1) Note. This might include, for example, semiconductor
diodes or transistors of diverse type.
Subclass:
153
Including electron discharge device:
This subclass is indented under subclass 151. Subject matter
utilizing a device which has electrical current flow between
two spaced electrodes in a gas, vapor or vacuum.
(1) Note. This might include, for example, vacuum or gas
tubes such as diodes, triodes or pentodes.
(2) Note. Additional control electrodes may be present.
Subclass:
154
Push-pull circuit:
This subclass is indented under subclass 153. Subject matter
wherein there are two electrical paths with common output
each of which contains an electron discharge device and in
which the respective voltages are 180 degrees out of phase
with respect to the other.
Subclass:
155
Percent modulation control or automatic amplitude control of
carrier or modulating signal:
This subclass is indented under subclass 149. Subject matter
in which amplitude control is exerted on the carrier, the
modulating signal, or the ratio therebetween without human
intervention.
SEE OR SEARCH THIS CLASS, SUBCLASS:
125 for amplitude control in a frequency modulator.
SEE OR SEARCH CLASS:
331, Oscillators, subclass 109 and 182+ for an oscillator
with amplitude control.
455, Telecommunications, subclass 116 for control of carrier
amplitude in a transmitter.
Subclass:
156
Over modulation prevention:
This subclass is indented under subclass 155. Subject matter
in which the automatic amplitude control maintains the ratio
of the modulating signal amplitude to the carrier signal
amplitude at a value of one or less.
Subclass:
157
Average carrier amplitude controlled by modulating signal:
This subclass is indented under subclass 155. Subject matter
in which the average unmodulated carrier amplitude is
adjusted to reflect the average modulating signal amplitude.
Subclass:
158
Carrier output suppressed during absence of modulating
signal:
This subclass is indented under subclass 155. Subject matter
in which the automatic control eliminates the carrier in
response to a lack of modulating signal.
SEE OR SEARCH THIS CLASS, SUBCLASS:
167 for a suppressed carrier, double sideband amplitude
modulator.
SEE OR SEARCH CLASS:
455, Telecommunications, subclass 116 for carrier amplitude
control in a telecommunications transmitter.
Subclass:
159
Including stabilization or alternatively distortion, noise,
or other interference prevention, reduction or compensation:
This subclass is indented under subclass 149. Subject matter
including the neutralization of an undesirable characteristic
of an amplitude modulator or its signals.
(1) Note. In some instances, distortion may be introduced
to the AM system in order to compensate for other inherent
distortion.
(2) Note. The neutralized characteristic might be some form
of system instability.
SEE OR SEARCH THIS CLASS, SUBCLASS:
107 for distortion or noise control in a pulse modulator.
123 for distortion or noise control in a frequency
modulator.
SEE OR SEARCH CLASS:
455, Telecommunications, 63 and 501+, for noise control in a
telecommunication system with separated transmitter and
receiver and subclass 114 for harmonic radiation control in a
transmitter.
Subclass:
160
Reduction or compensation of nonlinearity in modulation
characteristic:
This subclass is indented under subclass 159. Subject matter
which diminishes the undesired effects of a modulator element
or circuit whose output is not directly proportional to its
input.
Subclass:
161
Reduction of carrier phase or frequency variations or
modulation:
This subclass is indented under subclass 159. Subject matter
in which undesired fluctuations of either the phase or
frequency of the carrier are reduced.
SEE OR SEARCH THIS CLASS, SUBCLASS:
126 for frequency control in a frequency modulator.
SEE OR SEARCH CLASS:
455, Telecommunications, 75 for frequency stabilization in a
transceiver, subclass 113 for frequency control of a
frequency modulated transmitter and subclass 119 for
stabilizing the carrier frequency in a telecommunications
transmitter.
Subclass:
162
Using feedback to reduce distortion, noise, or other
interference:
This subclass is indented under subclass 159. Subject matter
in which a feedback signal is used to remove or control
distortion.
Subclass:
163
Including microwave or distributed parameter structure:
This subclass is indented under subclass 149. Subject matter
utilizing a structure or device which is peculiar to
microwave frequencies or which has resistance, inductance or
capacitance not concentrated in lumped circuit elements.
SEE OR SEARCH THIS CLASS, SUBCLASS:
129 for similar structure in a frequency modulator.
Subclass:
164
With discrete semiconductor device:
This subclass is indented under subclass 163. Subject matter
containing an electrical device whose constituent portions
are constructed from solid material having room temperature
conductivity between that of a conductor and an insulator and
which conductivity is typically modified through the addition
of small amounts of dopant.
(1) Note. This might include, for example, semiconductor
diodes or transistors of diverse type.
Subclass:
165
With electron discharge device:
This subclass is indented under subclass 163. Subject matter
combined with a device which has electrical current flow
between two spaced electrodes in a gas, vapor, or vacuum.
(1) Note. This might include, for example, vacuum or gas
tubes such as diodes, triodes or pentodes.
(2) Note. Additional control electrodes may be present.
Subclass:
166
Magnetron type:
This subclass is indented under subclass 165. Subject matter
in which an electron beam within the discharge device is
subject to a magnetic field.
SEE OR SEARCH CLASS:
315, Electric Lamp and Discharge Devices: Systems, subclass
5.13 and 39.51+ for a magnetron combined with diverse
circuit element.
331, Oscillators, subclass 5 for automatic frequency control
in a magnetron oscillator and subclasses 86+ for a magnetron
oscillator, per se.
Subclass:
167
Suppressed carrier double sideband type:
This subclass is indented under subclass 149. Subject matter
in which the carrier is suppressed continuously or
intermittently and both sidebands are intact.
SEE OR SEARCH CLASS:
455, Telecommunications, subclass 46 for a suppressed
carrier system having separated transmitter and receiver and
subclass 109 for a suppressed carrier amplitude modulated
transmitter.
Subclass:
168
Including discrete semiconductor device:
This subclass is indented under subclass 167. Subject matter
containing an electrical device whose constituent portions
are constructed from solid material having room temperature
conductivity between that of a conductor and an insulator and
which conductivity is typically modified through the addition
of small amounts dopant.
(1) Note. This might include, for example, semiconductor
diodes or transistors of diverse type.
Subclass:
169
Including electron discharge device:
This subclass is indented under subclass 167. Subject matter
utilizing a device which has electrical current flow between
two spaced electrodes in a gas, vapor or vacuum.
(1) Note. This might include, for example, vacuum or gas
tubes such as diodes, triodes or pentodes.
(2) Note. Additional control electrodes may be present.
Subclass:
170
Single or vestigial sideband type:
This subclass is indented under subclass 149. Subject matter
in which the final output contains less than two complete
sidebands with or without the carrier.
SEE OR SEARCH CLASS:
455, Telecommunications, subclass 47 for a single or
vestigial sideband system with separated transmitter and
receiver and subclass 109 for a single or vestigial sideband
amplitude modulated transmitter.
Subclass:
171
Including electron discharge device:
This subclass is indented under subclass 170. Subject matter
utilizing a device which has electrical current flow between
two spaced electrodes in a gas, vapor or vacuum.
(1) Note. This might include, for example, vacuum or gas
tubes such as diodes, triodes or pentodes.
(2) Note. Additional control electrodes may be present.
Subclass:
172
Modulating signal applied to a bridge circuit:
This subclass is indented under subclass 149. Subject matter
in which the carrier is applied to an impedance bridge in
which the impedance of at least one branch is varied in
accordance with the modulating signal.
Subclass:
173
Magnetic field varied by modulating signal:
This subclass is indented under subclass 149. Subject matter
in which the amplitude of the carrier is varied by varying a
magnetic field in accordance with the modulating signal.
(1) Note. Devices which may be used to vary a magnetic
field include saturable reactors and transformers.
Subclass:
174
Resistive or dissipative device controlled by modulating
signal (e.g., loss modulator):
This subclass is indented under subclass 149. Subject matter
in which the energy of the carrier is variably absorbed,
diverted or scattered in accordance with the modulating
signal.
SEE OR SEARCH CLASS:
455, Telecommunications, subclass 106 for a transmitter
utilizing absorption modulation.
Subclass:
175
Variable reactance controlled by modulating signal:
This subclass is indented under subclass 149. Subject matter
in which the amplitude of the carrier is varied by varying a
reactance in accordance with the modulating signal.
(1) Note. The variable reactance might be part of a tuning
circuit, variation of which may be used to vary the gain of a
circuit and thereby the amplitude of the carrier.
Subclass:
176
Nonlinear device controlled by modulating signal:
This subclass is indented under subclass 149. Subject matter
which includes a circuit element having an impedance which is
not directly proportional to the current passing through it
or the voltage applied to it and which controls the amplitude
of the carrier in accordance with the modulating signal.
(1) Note. Examples of nonlinear devices could be diodes,
nonlinear crystals, thyrite resistors, or electronic tubes.
Subclass:
177
Nonlinear discrete semiconductor device:
This subclass is indented under subclass 176. Subject matter
in which the controlled circuit element is an electrical
device whose constituent portions are constructed from solid
material having room temperature conductivity between that of
a conductor and an insulator and which conductivity is
typically modified through the addition of small amounts of
dopant.
Subclass:
178
Including discrete semiconductor device:
This subclass is indented under subclass 149. Subject matter
containing an electrical device whose constituent portions
are constructed from solid material having room temperature
conductivity between that of a conductor and an insulator and
which conductivity is typically modified through the addition
of small amounts of dopant.
(1) Note. This might include, for example, semiconductor
diodes or transistors of diverse type.
Subclass:
179
Including electron discharge device:
This subclass is indented under subclass 149. Subject matter
utilizing a device which has electrical current flow between
two spaced electrodes in a gas, vapor or vacuum.
(1) Note. This might include, for example, vacuum or gas
tubes such as diodes, triodes or pentodes.
(2) Note. Additional control electrodes may be present.
Subclass:
180
Push-pull circuit:
This subclass is indented under subclass 179. Subject matter
wherein there are two electrical paths with common output
each of which contains an electron discharge device and in
which the respective voltages are 180 degrees out of phase
with respect to the other.
Subclass:
181
Plate circuit modulation:
This subclass is indented under subclass 179. Subject matter
including an electronic tube which generates or amplifies the
carrier, and in which the modulating signal is applied to the
anode circuit of the tube or controls a circuit element in
the anode circuit.
(1) Note. This subclass includes circuits in which a
variable voltage under control of the modulating signal is
added to the anode supply voltage.
Subclass:
182
Grid circuit modulation:
This subclass is indented under subclass 179. Subject matter
including an electronic tube which generates or amplifies the
carrier, and in which the modulating signal is applied to the
grid circuit of the tube or controls a circuit element in the
grid circuit.
Subclass:
183
MODULATION CONVERTER HAVING PRE-MODULATED INPUT (E.G., FM TO
AM):
This subclass is indented under the class definition.
Subject matter in which the input to a system is a
repetitious electrical wave which has had a characteristic
varied in accordance with a modulating signal, and in which
the output of the system is a repetitious electrical wave
having a different characteristic varied.
(1) Note. This subclass excludes systems whose outputs are
pulse code modulated (PCM) or delta modulated. Such systems
are found in Class 341 subclasses 126+ and 143.
(2) Note. This subclass excludes systems having a plurality
of diverse type modulators wherein the input of a first
modulator is an intelligence and the output of this modulator
forms the input of a second modulator whose output is a
different form of modulation from its input. Such systems
are found in subclasses 108, 119+, 145, and 151+, where the
final output is pulse, frequency, phase or amplitude
modulated, respectively.
(3) Note. The combination of subject matter of this
subclass with a subsequent demodulator is classified in Class
329.
SEE OR SEARCH CLASS:
455, Telecommunications, appropriate subclasses, for
diverse-type conversion in a telecommunication transmitter or
receiver.
Subclass:
184
Between diverse pulse modulation types:
This subclass is indented under subclass 183. Subject matter
in which conversion occurs between diverse types of pulse
modulation.
(1) Note. This might include, for example, a pulse
amplitude modulation to pulse width modulation converter.
Subclass:
185
MISCELLANEOUS:
This subclass is indented under the class definition.
Subject matter not provided for in any of the preceding
subclasses.
Information Products Division -- Contacts
Questions regarding this report should be directed to:
U.S. Patent and Trademark Office
Information Products Division
PK3- Suite 441
Washington, DC 20231
tel: (703) 306-2600
FAX: (703) 306-2737
email: oeip@uspto.gov
Last Modified: 6 October 2000