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Outline
Indent Level
Color Curly Brackets (indicating CPC extensions to IPC) References Date Revised

CPC
COOPERATIVE PATENT CLASSIFICATION
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MODULATION (measuring, testing G01R; masers, lasers H01S; modulators specially adapted for use in the amplifiers H03F 3/38; modulating pulses H03K 7/00; so-called modulators capable only of a switching between predetermined states of amplitude, frequency or phase H03K 17/00, H04L; coding, decoding or code conversion, in general H03M; synchronous modulators specially adapted for colour television H04N 9/65)
NOTE
-
This subclass covers only modulation, keying, or interruption of sinusoidal oscillations or electromagnetic waves, the modulating signal having any desired waveform.

In this subclass, circuits usable both as modulator and demodulator are classified in the group dealing with the type of modulator involved.

WARNING
-
The following IPC groups are not used in the CPC scheme. Subject matter covered by these groups is classified in the following CPC groups :
H03C1/38 to H03C1/44 covered by H03C 1/36

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Amplitude modulation (H03C 5/00, H03C 7/00 take precedence)
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H03C 1/02
.
Details
H03C 1/04
. .
Means in or combined with modulating stage for reducing angle modulation
H03C 1/06
. .
Modification of modulator to reduce distorsion, e.g. by feedback, and clearly applicable to more than one type of modulator
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.
by means of variable impedance element (H03C 1/28 to H03C 1/34, H03C 1/46 to H03C 1/52, H03C 1/62 take precedence)
H03C 1/10
. .
the element being a current-dependent inductor
H03C 1/12
. .
the element being a voltage-dependent capacitor
H03C 1/14
. .
the element being a diode
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.
by means of discharge device having at least three electrodes (H03C 1/28 to H03C 1/34, H03C 1/50, H03C 1/52, H03C 1/62 take precedence)
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H03C 1/18
. .
carrier applied to control grid
H03C 1/20
. . .
modulating signal applied to anode
H03C 1/22
. . .
modulating signal applied to same grid
H03C 1/24
. . .
modulating signal applied to different grid
H03C 1/26
. . .
modulating signal applied to cathode
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H03C 1/28
.
by means of transit-time tube
H03C 1/30
. .
by means of a magnetron
H03C 1/32
.
by deflection of electron beam in discharge tube
H03C 1/34
.
by means of light-sensitive element
.
by means of semiconductor device having at least three electrodes (H03C 1/34, H03C 1/50, H03C 1/52, H03C 1/62 take precedence)
H03C 1/46
.
Modulators with mechanically or acoustically driven parts
H03C 1/48
.
by means of Hall-effect devices
.
by converting angle modulation to amplitude modulation (H03C 1/28 to H03C 1/34, H03C 1/46, H03C 1/48 take precedence)
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.
Modulators in which carrier or one side-band are wholly or partially suppressed (H03C 1/28 to H03C 1/34, H03C 1/46, H03C 1/48 take precedence)
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H03C 1/54
. .
Balanced modulators, e.g. bridge type, ring type, double balanced type
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H03C 1/542
. . .
{
comprising semiconductor devices with at least three electrodes
}
H03C 1/545
. . . .
{
using bipolar transistors
}
. . . .
{
using field-effect transistors
}
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H03C 1/56
. . .
comprising variable two-pole elements only
H03C 1/58
. . . .
comprising diodes
H03C 1/60
. .
with one sideband wholly or partially suppressed
.
Modulators in which amplitude of carrier component in output is dependent upon strength of modulating signal, e.g. no carrier output when no modulating signal is present (H03C 1/28 to H03C 1/34, H03C 1/46, H03C 1/48 take precedence)
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Angle modulation (H03C 5/00, H03C 7/00 take precedence)
H03C 3/005
.
{
Circuits for asymmetric modulation
}
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H03C 3/02
.
Details
H03C 3/04
. .
Means in or combined with modulating stage for reducing amplitude modulation
. .
Means for changing frequency deviation
{
for demodulation H03D 3/003, H03D 3/242
}
H03C 3/08
. .
Modification of modulator to linearise modulation, e.g. by feedback, and clearly applicable to more than one type of modulator
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. .
Modifications of modulator for regulating the mean frequency
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. . .
{
using a phase locked loop
}
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H03C 3/0916
. . . .
{
with frequency divider or counter in the loop
}
H03C 3/0925
. . . . .
{
applying frequency modulation at the divider in the feedback loop
}
. . . . .
{
using fractional frequency division in the feedback loop of the phase locked loop
}
H03C 3/0941
. . . .
{
applying frequency modulation at more than one point in the loop
}
H03C 3/095
. . . .
{
applying frequency modulation to the loop in front of the voltage controlled oscillator
}
H03C 3/0958
. . . .
{
applying frequency modulation by varying the characteristics of the voltage controlled oscillator
}
H03C 3/0966
. . . .
{
modulating the reference clock
}
H03C 3/0975
. . . .
{
applying frequency modulation in the phase locked loop at components other than the divider, the voltage controlled oscillator or the reference clock
}
H03C 3/0983
. . . .
{
containing in the loop a mixer other than for phase detection
}
H03C 3/0991
. . . .
{
including calibration means or calibration methods
}
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.
by means of variable impedance (H03C 3/30 to H03C 3/38 take precedence)
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H03C 3/12
. .
by means of a variable reactive element
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H03C 3/14
. . .
simulated by circuit comprising active element with at least three electrodes, e.g. reactance-tube circuit
H03C 3/145
. . . .
{
by using semiconductor elements
}
H03C 3/16
. . . .
in which the active element simultaneously serves as the active element of an oscillator
H03C 3/18
. . .
the element being a current-dependent inductor
H03C 3/20
. . .
the element being a voltage-dependent capacitor
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H03C 3/22
. . .
the element being a semiconductor diode, e.g. varicap diode
. . . .
{
using bipolar transistors (H03C 3/227 takes precedence)
}
. . . .
{
using field effect transistors (H03C 3/227 takes precedence)
}
H03C 3/227
. . . .
{
using a combination of bipolar transistors and field effect transistors
}
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H03C 3/24
. .
by means of a variable resistive element, e.g. tube
H03C 3/245
. . .
{
by using semiconductor elements
}
H03C 3/26
. . .
comprising two elements controlled in push-pull by modulating signal
H03C 3/28
. .
using variable impedance driven mechanically or acoustically
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H03C 3/30
.
by means of transit-time tube
H03C 3/32
. .
the tube being a magnetron
H03C 3/34
.
by deflection of electron beam in discharge tube
H03C 3/36
.
by means of light-sensitive element
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H03C 3/38
.
by converting amplitude modulation to angle modulation
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H03C 3/40
. .
using two signal paths the outputs of which have a predetermined phase difference and at least one output being amplitude-modulated
. . .
{
using two quadrature frequency conversion stages in cascade
}
H03C 3/406
. . .
{
using a feedback loop containing mixers or demodulators
}
.
by means of electromechanical devices (H03C 3/28 takes precedence)
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Amplitude modulation and angle modulation produced simultaneously or at will by the same modulating signal (H03C 7/00 takes precedence)
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H03C 5/02
.
by means of transit-time tube
H03C 5/04
. .
the tube being a magnetron
H03C 5/06
.
by deflection of electron beam in discharge tube
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Modulating electromagnetic waves (modulating light G02F 1/00; for generating oscillations H03B, H03K)
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H03C 7/02
.
in transmission line, waveguide, cavity resonator, or radiation field of aerial
H03C 7/022
. .
{
using ferromagnetic devices, e.g. ferrites
}
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. .
{
using semiconductor devices
}
H03C 7/027
. . .
{
using diodes
}
. .
Polarisation of transmitted wave being modulated
{
H03C 7/022 takes precedence
}
Subject matter not provided for in other groups of this subclass
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Indexing scheme relating to details of modulators or modulation methods covered by H03C
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H03C 2200/0004
.
Circuit elements of modulators
H03C 2200/0008
. .
Variable capacitors, e.g. a varicap, a varactor or a variable capacitance of a diode or transistor
H03C 2200/0012
. .
Emitter or source coupled transistor pairs or long tail pairs
H03C 2200/0016
. .
Pre-emphasis or de-emphasis circuits
. .
Filters with particular characteristics
. .
Gilbert multipliers
H03C 2200/0029
. .
Memory circuits, e.g. ROMs, RAMs, EPROMs, latches, shift registers
H03C 2200/0033
. .
Transmission lines, e.g. striplines, microstrips or coplanar lines
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H03C 2200/0037
.
Functional aspects of modulators
H03C 2200/0041
. .
Calibration of modulators
H03C 2200/0045
. .
Pulse width, duty cycle or on/off ratio
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H03C 2200/005
. .
Modulation sensitivity
H03C 2200/0054
. . .
Filtering of the input modulating signal for obtaining a constant sensitivity of frequency modulation
H03C 2200/0058
. .
Quadrature arrangements
H03C 2200/0062
. .
Lowering the supply voltage and saving power
H03C 2200/0066
. .
Reduction of carrier leakage or the suppression of the carrier
. .
with one sideband wholly or partially suppressed
H03C 2200/0075
. .
FM modulation down to DC
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. .
Measures to linearise modulation or reduce distortion of modulation characteristics
H03C 2200/0083
. . .
Predistortion of input modulating signal to obtain a linear modulation characteristic
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H03C 2200/0087
. .
Measures to address temperature induced variations of modulation
H03C 2200/0091
. . .
by stabilising the temperature
H03C 2200/0095
. . .
by compensating temperature induced variations
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Last Modified: 10/10/2013