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Color Curly Brackets (indicating CPC extensions to IPC) References Date Revised
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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) [2013‑01]
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) [2013‑01]
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H03C 1/02
.
Details [2013‑01]
H03C 1/04
. .
Means in or combined with modulating stage for reducing angle modulation [2013‑01]
H03C 1/06
. .
Modification of modulator to reduce distorsion, e.g. by feedback, and clearly applicable to more than one type of modulator [2013‑01]
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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) [2013‑01]
H03C 1/10
. .
the element being a current-dependent inductor [2013‑01]
H03C 1/12
. .
the element being a voltage-dependent capacitor [2013‑01]
H03C 1/14
. .
the element being a diode [2013‑01]
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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) [2013‑01]
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H03C 1/18
. .
carrier applied to control grid [2013‑01]
H03C 1/20
. . .
modulating signal applied to anode [2013‑01]
H03C 1/22
. . .
modulating signal applied to same grid [2013‑01]
H03C 1/24
. . .
modulating signal applied to different grid [2013‑01]
H03C 1/26
. . .
modulating signal applied to cathode [2013‑01]
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H03C 1/28
.
by means of transit-time tube [2013‑01]
H03C 1/30
. .
by means of a magnetron [2013‑01]
H03C 1/32
.
by deflection of electron beam in discharge tube [2013‑01]
H03C 1/34
.
by means of light-sensitive element [2013‑01]
.
by means of semiconductor device having at least three electrodes (H03C 1/34, H03C 1/50, H03C 1/52, H03C 1/62 take precedence) [2013‑01]
H03C 1/46
.
Modulators with mechanically or acoustically driven parts [2013‑01]
H03C 1/48
.
by means of Hall-effect devices [2013‑01]
.
by converting angle modulation to amplitude modulation (H03C 1/28 to H03C 1/34, H03C 1/46, H03C 1/48 take precedence) [2013‑01]
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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) [2013‑01]
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H03C 1/54
. .
Balanced modulators, e.g. bridge type, ring type, double balanced type [2013‑01]
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H03C 1/542
. . .
{
comprising semiconductor devices with at least three electrodes
}
[2013‑01]
H03C 1/545
. . . .
{
using bipolar transistors
}
[2013‑01]
. . . .
{
using field-effect transistors
}
[2013‑01]
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H03C 1/56
. . .
comprising variable two-pole elements only [2013‑01]
H03C 1/58
. . . .
comprising diodes [2013‑01]
H03C 1/60
. .
with one sideband wholly or partially suppressed [2013‑01]
.
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) [2013‑01]
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Angle modulation (H03C 5/00, H03C 7/00 take precedence) [2013‑01]
H03C 3/005
.
{
Circuits for asymmetric modulation
}
[2013‑01]
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H03C 3/02
.
Details [2013‑01]
H03C 3/04
. .
Means in or combined with modulating stage for reducing amplitude modulation [2013‑01]
. .
Means for changing frequency deviation
{
(for demodulation H03D 3/003, H03D 3/242)
}
[2013‑01]
H03C 3/08
. .
Modification of modulator to linearise modulation, e.g. by feedback, and clearly applicable to more than one type of modulator [2013‑01]
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. .
Modifications of modulator for regulating the mean frequency [2013‑01]
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. . .
{
using a phase locked loop
}
[2013‑01]
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H03C 3/0916
. . . .
{
with frequency divider or counter in the loop
}
[2013‑01]
H03C 3/0925
. . . . .
{
applying frequency modulation at the divider in the feedback loop
}
[2013‑01]
. . . . .
{
using fractional frequency division in the feedback loop of the phase locked loop
}
[2013‑01]
H03C 3/0941
. . . .
{
applying frequency modulation at more than one point in the loop
}
[2013‑01]
H03C 3/095
. . . .
{
applying frequency modulation to the loop in front of the voltage controlled oscillator
}
[2013‑01]
H03C 3/0958
. . . .
{
applying frequency modulation by varying the characteristics of the voltage controlled oscillator
}
[2013‑01]
H03C 3/0966
. . . .
{
modulating the reference clock
}
[2013‑01]
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
}
[2013‑01]
H03C 3/0983
. . . .
{
containing in the loop a mixer other than for phase detection
}
[2013‑01]
H03C 3/0991
. . . .
{
including calibration means or calibration methods
}
[2013‑01]
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.
by means of variable impedance (H03C 3/30 to H03C 3/38 take precedence) [2013‑01]
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H03C 3/12
. .
by means of a variable reactive element [2013‑01]
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H03C 3/14
. . .
simulated by circuit comprising active element with at least three electrodes, e.g. reactance-tube circuit [2013‑01]
H03C 3/145
. . . .
{
by using semiconductor elements
}
[2013‑01]
H03C 3/16
. . . .
in which the active element simultaneously serves as the active element of an oscillator [2013‑01]
H03C 3/18
. . .
the element being a current-dependent inductor [2013‑01]
H03C 3/20
. . .
the element being a voltage-dependent capacitor [2013‑01]
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H03C 3/22
. . .
the element being a semiconductor diode, e.g. varicap diode [2013‑01]
. . . .
{
using bipolar transistors (H03C 3/227 takes precedence)
}
[2013‑01]
. . . .
{
using field effect transistors (H03C 3/227 takes precedence)
}
[2013‑01]
H03C 3/227
. . . .
{
using a combination of bipolar transistors and field effect transistors
}
[2013‑01]
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H03C 3/24
. .
by means of a variable resistive element, e.g. tube [2013‑01]
H03C 3/245
. . .
{
by using semiconductor elements
}
[2013‑01]
H03C 3/26
. . .
comprising two elements controlled in push-pull by modulating signal [2013‑01]
H03C 3/28
. .
using variable impedance driven mechanically or acoustically [2013‑01]
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H03C 3/30
.
by means of transit-time tube [2013‑01]
H03C 3/32
. .
the tube being a magnetron [2013‑01]
H03C 3/34
.
by deflection of electron beam in discharge tube [2013‑01]
H03C 3/36
.
by means of light-sensitive element [2013‑01]
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H03C 3/38
.
by converting amplitude modulation to angle modulation [2013‑01]
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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 [2013‑01]
. . .
{
using two quadrature frequency conversion stages in cascade
}
[2013‑01]
H03C 3/406
. . .
{
using a feedback loop containing mixers or demodulators
}
[2013‑01]
.
by means of electromechanical devices (H03C 3/28 takes precedence) [2013‑01]
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Amplitude modulation and angle modulation produced simultaneously or at will by the same modulating signal (H03C 7/00 takes precedence) [2013‑01]
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H03C 5/02
.
by means of transit-time tube [2013‑01]
H03C 5/04
. .
the tube being a magnetron [2013‑01]
H03C 5/06
.
by deflection of electron beam in discharge tube [2013‑01]
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Modulating electromagnetic waves (modulating light G02F 1/00; for generating oscillations H03B, H03K) [2013‑01]
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H03C 7/02
.
in transmission line, waveguide, cavity resonator, or radiation field of aerial [2013‑01]
H03C 7/022
. .
{
using ferromagnetic devices, e.g. ferrites
}
[2013‑01]
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. .
{
using semiconductor devices
}
[2013‑01]
H03C 7/027
. . .
{
using diodes
}
[2013‑01]
. .
Polarisation of transmitted wave being modulated
{
(H03C 7/022 takes precedence)
}
[2013‑01]
Subject matter not provided for in other groups of this subclass [2013‑01]
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Indexing scheme relating to details of modulators or modulation methods covered by H03C [2013‑01]
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H03C 2200/0004
.
Circuit elements of modulators [2013‑01]
H03C 2200/0008
. .
Variable capacitors, e.g. a varicap, a varactor or a variable capacitance of a diode or transistor [2013‑01]
H03C 2200/0012
. .
Emitter or source coupled transistor pairs or long tail pairs [2013‑01]
H03C 2200/0016
. .
Pre-emphasis or de-emphasis circuits [2013‑01]
. .
Filters with particular characteristics [2013‑01]
. .
Gilbert multipliers [2013‑01]
H03C 2200/0029
. .
Memory circuits, e.g. ROMs, RAMs, EPROMs, latches, shift registers [2013‑01]
H03C 2200/0033
. .
Transmission lines, e.g. striplines, microstrips or coplanar lines [2013‑01]
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H03C 2200/0037
.
Functional aspects of modulators [2013‑01]
H03C 2200/0041
. .
Calibration of modulators [2013‑01]
H03C 2200/0045
. .
Pulse width, duty cycle or on/off ratio [2013‑01]
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H03C 2200/005
. .
Modulation sensitivity [2013‑01]
H03C 2200/0054
. . .
Filtering of the input modulating signal for obtaining a constant sensitivity of frequency modulation [2013‑01]
H03C 2200/0058
. .
Quadrature arrangements [2013‑01]
H03C 2200/0062
. .
Lowering the supply voltage and saving power [2013‑01]
H03C 2200/0066
. .
Reduction of carrier leakage or the suppression of the carrier [2013‑01]
. .
with one sideband wholly or partially suppressed [2013‑01]
H03C 2200/0075
. .
FM modulation down to DC [2013‑01]
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. .
Measures to linearise modulation or reduce distortion of modulation characteristics [2013‑01]
H03C 2200/0083
. . .
Predistortion of input modulating signal to obtain a linear modulation characteristic [2013‑01]
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H03C 2200/0087
. .
Measures to address temperature induced variations of modulation [2013‑01]
H03C 2200/0091
. . .
by stabilising the temperature [2013‑01]
H03C 2200/0095
. . .
by compensating temperature induced variations [2013‑01]
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Last Modified: 10/10/2013