1. CPC Sections
  2. CPC Section H
  3. CPC Class H03
  4. CPC Subclass H03D
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CPC
COOPERATIVE PATENT CLASSIFICATION
​​
H03D
DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TO ANOTHER (masers, lasers H01S; circuits capable of acting both as modulator and demodulator H03C; details applicable to both modulators and frequency-changers H03C; demodulating pulses H03K 9/00; transforming types of pulse modulation H03K 11/00; coding, decoding or code conversion, in general H03M; repeater stations H04B 7/14; demodulators adapted for ac systems of digital information transmission H04L 27/00; synchronous demodulators adapted for colour television H04N 9/66) [2020-05]
NOTE

  • This subclass covers only:
    • demodulation or transference of signals modulated on a sinusoidal carrier or on electromagnetic waves;
    • comparing phase or frequency of two mutually-independent oscillations.
WARNING

  • In this subclass non-limiting references (in the sense of paragraph 39 of the Guide to the IPC) may still be displayed in the scheme.
H03D 1/00
Demodulation of amplitude-modulated oscillations (H03D 5/00, H03D 9/00, H03D 11/00 take precedence) [2013-01]
H03D 1/02
.
Details [2013-01]
H03D 1/04
. .
Modifications of demodulators to reduce interference by undesired signals [2013-01]
H03D 1/06
. .
Modifications of demodulators to reduce distortion, e.g. by negative feedback [2013-01]
H03D 1/08
.
by means of non-linear two-pole elements (H03D 1/22, H03D 1/26, H03D 1/28 take precedence) [2013-01]
H03D 1/10
. .
of diodes [2013-01]
H03D 1/12
. . .
with provision for equalising ac and dc loads [2013-01]
H03D 1/14
.
by means of non-linear elements having more than two poles (H03D 1/22, H03D 1/26, H03D 1/28 take precedence) [2013-01]
H03D 1/16
. .
of discharge tubes [2013-01]
H03D 1/18
. .
of semiconductor devices [2013-01]
H03D 1/20
. .
with provision for preventing undesired type of demodulation, e.g. preventing anode detection in a grid detection circuit [2013-01]
H03D 1/22
.
Homodyne or synchrodyne circuits {(receiver circuits H04B 1/30)} [2013-01]
H03D 1/2209
. .
{Decoders for simultaneous demodulation and decoding of signals composed of a sum-signal and a suppressed carrier, amplitude modulated by a difference signal, e.g. stereocoders} [2013-01]
H03D 1/2218
. . .
{using diodes for the decoding} [2013-01]
H03D 1/2227
. . .
{using switches for the decoding (diodes used as switches H03D 1/2218)} [2013-01]
H03D 1/2236
. . .
{using a phase locked loop} [2013-01]
H03D 1/2245
. .
{using two quadrature channels (H03D 1/2209 takes precedence)} [2013-01]
H03D 1/2254
. . .
{and a phase locked loop} [2013-01]
H03D 2001/2263
. . . .
{including a counter or a divider in the PLL} [2013-01]
H03D 1/2272
. .
{using FET's (H03D 1/2209, H03D 1/2245 and H03D 1/2281 take precedence)} [2013-01]
H03D 1/2281
. .
{using a phase locked loop (H03D 1/2236 and H03D 1/2254 take precedence)} [2013-01]
H03D 1/229
. .
{using at least a two emittor-coupled differential pair of transistors (H03D 1/2209 - H03D 1/2281 take precedence)} [2016-05]
H03D 1/24
. .
for demodulation of signals wherein one sideband or the carrier has been wholly or partially suppressed {(receiver circuits H04B 1/302)} [2013-01]
H03D 1/26
.
by means of transit-time tubes [2013-01]
H03D 1/28
.
by deflecting an electron beam in a discharge tube (H03D 1/26 takes precedence) [2013-01]
H03D 3/00
Demodulation of angle-, {frequency- or phase-} modulated oscillations (H03D 5/00, H03D 9/00, H03D 11/00 take precedence) [2013-01]
H03D 3/001
.
{Details of arrangements applicable to more than one type of frequency demodulator (H03D 3/28 takes precedence)} [2013-01]
H03D 3/002
. .
{Modifications of demodulators to reduce interference by undesired signals (H03D 3/248 takes precedence)} [2013-01]
H03D 3/003
. .
{Arrangements for reducing frequency deviation, e.g. by negative frequency feedback (combined with a phase locked loop demodulator H03D 3/242; changing frequency deviation for modulators H03C 3/06)} [2013-01]
H03D 3/004
. . .
{wherein the demodulated signal is used for controlling an oscillator, e.g. the local oscillator} [2013-01]
H03D 3/005
. . .
{wherein the demodulated signal is used for controlling a bandpass filter (automatic bandwidth control H03G; automatic frequency control H03J 7/02)} [2013-01]
H03D 3/006
.
{by sampling the oscillations and further processing the samples, e.g. by computing techniques (H03D 3/007 takes precedence)} [2013-01]
H03D 3/007
.
{by converting the oscillations into two quadrature related signals (H03D 3/245 takes precedence)} [2013-01]
H03D 3/008
. .
{Compensating DC offsets} [2013-01]
H03D 3/009
. .
{Compensating quadrature phase or amplitude imbalances} [2013-01]
H03D 3/02
.
by detecting phase difference between two signals obtained from input signal (H03D 3/28 - H03D 3/32 take precedence; {muting in frequency-modulation receivers H03G 3/28}; limiting arrangements H03G 11/00) [2016-05]
H03D 3/04
. .
by counting or integrating cycles of oscillations {(arrangements for measuring frequencies G01R 23/10)} [2013-01]
H03D 3/06
. .
by combining signals additively or in product demodulators [2013-01]
H03D 3/08
. . .
by means of diodes, e.g. Foster-Seeley discriminator [2013-01]
H03D 3/10
. . . .
in which the diodes are simultaneously conducting during the same half period of the signal, e.g. radio detector [2013-01]
H03D 3/12
. . .
by means of discharge tubes having more than two electrodes [2013-01]
H03D 3/14
. . .
by means of semiconductor devices having more than two electrodes [2013-01]
H03D 3/16
. . .
by means of electromechanical resonators [2013-01]
H03D 3/18
. .
by means of synchronous gating arrangements [2013-01]
H03D 3/20
. . .
producing pulses whose amplitude or duration depends on phase difference [2013-01]
H03D 3/22
. .
by means of active elements with more than two electrodes to which two signals are applied derived from the signal to be demodulated and having a phase difference related to the frequency deviation, e.g. phase detector [2013-01]
H03D 3/24
. .
Modifications of demodulators to reject or remove amplitude variations by means of locked-in oscillator circuits [2013-01]
H03D 3/241
. . .
{the oscillator being part of a phase locked loop} [2013-01]
H03D 3/242
. . . .
{combined with means for controlling the frequency of a further oscillator, e.g. for negative frequency feedback or AFC} [2013-01]
H03D 3/244
. . . .
{combined with means for obtaining automatic gain control} [2013-01]
H03D 3/245
. . . .
{using at least twophase detectors in the loop (H03D 3/244 takes precedence; in general H03L 7/087)} [2013-01]
H03D 3/247
. . . .
{using a controlled phase shifter (in general H03L 7/081)} [2013-01]
H03D 3/248
. . . .
{with means for eliminating interfering signals, e.g. by multiple phase locked loops (multiple loops in general H03L 7/07, H03L 7/22)} [2013-01]
H03D 3/26
.
by means of sloping amplitude/frequency characteristic of tuned or reactive circuit (H03D 3/28 - H03D 3/32 takes precedence) [2016-05]
H03D 3/28
.
Modifications of demodulators to reduce effects of temperature variations ({automatic frequency regulation in receivers H03J}; automatic frequency control H03L) [2013-01]
H03D 3/30
.
by means of transit-time tubes [2013-01]
H03D 3/32
.
by deflecting an electron beam in a discharge tube (H03D 3/30 takes precedence) [2013-01]
H03D 3/34
.
by means of electromechanical devices (H03D 3/16 takes precedence) [2013-01]
H03D 5/00
Circuits for demodulating amplitude-modulated or angle-modulated oscillations at will (H03D 9/00, H03D 11/00 take precedence) [2013-01]
H03D 7/00
Transference of modulation from one carrier to another, e.g. frequency-changing (H03D 9/00, H03D 11/00 take precedence; dielectric amplifiers, magnetic amplifiers, parametric amplifiers used as a frequency-changers H03F) [2013-01]
H03D 7/005
.
{by means of superconductive devices} [2013-01]
H03D 7/02
.
by means of diodes (H03D 7/14 - H03D 7/22 take precedence) [2016-05]
H03D 7/04
. .
having {a partially} negative resistance characteristic, e.g. tunnel diode [2013-01]
H03D 7/06
.
by means of discharge tubes having more than two electrodes (H03D 7/14 - H03D 7/22 take precedence) [2016-05]
H03D 7/08
. .
the signals to be mixed being applied between the same two electrodes [2013-01]
H03D 7/10
. .
the signals to be mixed being applied between different pairs of electrodes [2013-01]
H03D 7/12
.
by means of semiconductor devices having more than two electrodes (H03D 7/14 - H03D 7/22 take precedence) [2016-05]
H03D 7/125
. .
{with field effect transistors} [2013-01]
H03D 7/14
.
Balanced arrangements [2013-01]
H03D 7/1408
. .
{with diodes} [2013-01]
H03D 7/1416
. .
{with discharge tubes having more than two electrodes} [2013-01]
H03D 7/1425
. .
{with transistors} [2019-01]
H03D 7/1433
. . .
{using bipolar transistors (H03D 7/145 takes precedence)} [2013-01]
H03D 7/1441
. . .
{using field-effect transistors (H03D 7/145 takes precedence)} [2013-01]
H03D 7/145
. . .
{using a combination of bipolar transistors and field-effect transistors} [2013-01]
H03D 7/1458
. . .
{Double balanced arrangements, i.e. where both input signals are differential} [2013-01]
H03D 7/1466
. . .
{Passive mixer arrangements} [2013-01]
H03D 7/1475
. . .
{Subharmonic mixer arrangements} [2013-01]
H03D 7/1483
. . .
{comprising components for selecting a particular frequency component of the output} [2013-01]
H03D 7/1491
. . .
{Arrangements to linearise a transconductance stage of a mixer arrangement} [2013-01]
H03D 7/16
.
Multiple-frequency-changing [2013-01]
H03D 7/161
. .
{all the frequency changers being connected in cascade} [2013-01]
H03D 7/163
. . .
{the local oscillations of at least two of the frequency changers being derived from a single oscillator} [2013-01]
H03D 7/165
. .
{at least two frequency changers being located in different paths, e.g. in two paths with carriers in quadrature (combined with amplitude demodulation H03D 1/2245, combined with angle demodulation H03D 3/007; N-path filters H03H 19/002)} [2013-01]
H03D 7/166
. . .
{using two or more quadrature frequency translation stages} [2013-01]
H03D 7/168
. . . .
{using a feedback loop containing mixers or demodulators} [2013-01]
H03D 7/18
.
Modifications of frequency-changers for eliminating image frequencies {(H03D 7/16 takes precedence)} [2013-01]
H03D 7/20
.
by means of transit-time tubes [2013-01]
H03D 7/22
.
by deflecting an electron beam in a discharge tube (H03D 7/20 takes precedence) [2013-01]
H03D 9/00
Demodulation or transference of modulation of modulated electromagnetic waves (demodulating light, transferring modulation in light waves G02F 2/00) [2013-01]
H03D 9/02
.
Demodulation using distributed inductance and capacitance, e.g. in feeder lines [2013-01]
H03D 9/04
. .
for angle-modulated oscillations [2013-01]
H03D 9/06
.
Transference of modulation using distributed inductance and capacitance [2013-01]
H03D 9/0608
. .
{by means of diodes} [2013-01]
H03D 9/0616
. . .
{mounted in a hollow waveguide (H03D 9/0641 takes precedence)} [2013-01]
H03D 9/0625
. . .
{mounted in a coaxial resonator structure} [2013-01]
H03D 9/0633
. . .
{mounted on a stripline circuit} [2013-01]
H03D 9/0641
. . . .
{located in a hollow waveguide} [2013-01]
H03D 9/065
. .
{by means of discharge tubes having more than two electrodes} [2013-01]
H03D 9/0658
. .
{by means of semiconductor devices having more than two electrodes} [2013-01]
H03D 9/0666
. . .
{using bipolar transistors (H03D 9/0683 takes precedence)} [2013-01]
H03D 9/0675
. . .
{using field effect transistors (H03D 9/0683 takes precedence)} [2013-01]
H03D 9/0683
. . .
{using a combination of bipolar transistors and field effect transistors} [2013-01]
H03D 2009/0691
. .
{by means of superconductive devices} [2013-01]
H03D 11/00
Super-regenerative demodulator circuits {(applications in responders G01S)} [2013-01]
H03D 11/02
.
for amplitude-modulated oscillations [2013-01]
H03D 11/04
. .
by means of semiconductor devices having more than two electrodes [2013-01]
H03D 11/06
.
for angle-modulated oscillations [2013-01]
H03D 11/08
. .
by means of semiconductor devices having more than two electrodes [2013-01]
H03D 13/00
Circuits for comparing the phase or frequency of two mutually-independent oscillations {(measuring phase G01R 25/00; phase-discriminators with yes/no output G01R 25/005)} [2017-08]
H03D 13/001
.
{in which a pulse counter is used followed by a conversion into an analog signal} [2013-01]
H03D 13/002
. .
{the counter being an up-down counter} [2013-01]
H03D 13/003
.
{in which both oscillations are converted by logic means into pulses which are applied to filtering or integrating means} [2013-01]
H03D 13/004
. .
{the logic means delivering pulses at more than one terminal, e.g. up and down pulses} [2013-01]
H03D 13/005
.
{in which one of the oscillations is, or is converted into, a signal having a special waveform, e.g. triangular} [2013-01]
H03D 13/006
. .
{and by sampling this signal by narrow pulses obtained from the second oscillation} [2013-01]
H03D 13/007
.
{by analog multiplication of the oscillations or by performing a similar analog operation on the oscillations} [2013-01]
H03D 13/008
. .
{using transistors} [2013-01]
H03D 13/009
. .
{using diodes} [2013-01]
H03D 99/00
Subject matter not provided for in other groups of this subclass [2013-01]
H03D 2200/00
Indexing scheme relating to details of demodulation or transference of modulation from one carrier to another covered by H03D [2013-01]
H03D 2200/0001
.
Circuit elements of demodulators [2013-01]
H03D 2200/0003
. .
Rat race couplers [2013-01]
H03D 2200/0005
. .
Wilkinson power dividers or combiners [2013-01]
H03D 2200/0007
. .
Dual gate field effect transistors [2013-01]
H03D 2200/0009
. .
Emitter or source coupled transistor pairs or long tail pairs [2013-01]
H03D 2200/0011
. .
Diodes [2013-01]
H03D 2200/0013
. . .
Diodes connected in a ring configuration [2013-01]
H03D 2200/0015
. . .
Diodes connected in a star configuration [2013-01]
H03D 2200/0017
. .
Intermediate frequency filter [2013-01]
H03D 2200/0019
. .
Gilbert multipliers [2013-01]
H03D 2200/0021
. .
Frequency multipliers [2013-01]
H03D 2200/0023
. .
Balun circuits [2013-01]
H03D 2200/0025
. .
Gain control circuits [2013-01]
H03D 2200/0027
. . .
including arrangements for assuring the same gain in two paths [2013-01]
H03D 2200/0029
. .
Loop circuits with controlled phase shift [2013-01]
H03D 2200/0031
. .
PLL circuits with quadrature locking, e.g. a Costas loop [2013-01]
H03D 2200/0033
. .
Current mirrors [2013-01]
H03D 2200/0035
. .
Digital multipliers and adders used for detection [2013-01]
H03D 2200/0037
. .
Diplexers [2013-01]
H03D 2200/0039
. .
Exclusive OR logic circuits [2013-01]
H03D 2200/0041
.
Functional aspects of demodulators [2013-01]
H03D 2200/0043
. .
Bias and operating point [2013-01]
H03D 2200/0045
. .
Calibration of demodulators [2013-01]
H03D 2200/0047
. .
Offset of DC voltage or frequency [2013-01]
H03D 2200/0049
. .
Analog multiplication for detection [2013-01]
H03D 2200/005
. .
Analog to digital conversion [2013-01]
H03D 2200/0052
. .
Digital to analog conversion [2013-01]
H03D 2200/0054
. .
Digital filters [2013-01]
H03D 2200/0056
. . .
including a digital decimation filter [2013-01]
H03D 2200/0058
. . .
using a digital filter with interpolation [2013-01]
H03D 2200/006
. .
Signal sampling [2013-01]
H03D 2200/0062
. . .
Computation of input samples, e.g. successive samples [2013-01]
H03D 2200/0064
. .
Detection of passages through null of a signal [2013-01]
H03D 2200/0066
. .
Mixing [2013-01]
H03D 2200/0068
. . .
by computation [2013-01]
H03D 2200/007
. . .
by using a logic circuit, e.g. flipflop, XOR [2013-01]
H03D 2200/0072
. . .
by complex multiplication [2013-01]
H03D 2200/0074
. . .
using a resistive mixer or a passive mixer [2013-01]
H03D 2200/0076
. . .
using a distributed mixer [2013-01]
H03D 2200/0078
. . .
using a switched phase shifter or delay line [2013-01]
H03D 2200/008
. .
Hilbert type transformation [2013-01]
H03D 2200/0082
. .
Quadrature arrangements [2013-01]
H03D 2200/0084
. .
Lowering the supply voltage and saving power [2013-01]
H03D 2200/0086
. .
Reduction or prevention of harmonic frequencies [2013-01]
H03D 2200/0088
. .
Reduction of intermodulation, nonlinearities, adjacent channel interference; intercept points of harmonics or intermodulation products [2013-01]
H03D 2200/009
. .
Reduction of local oscillator or RF leakage [2013-01]
H03D 2200/0092
. .
Detection or reduction of fading in multipath transmission arrangements [2013-01]
H03D 2200/0094
. .
Measures to address temperature induced variations of demodulation [2013-01]
H03D 2200/0096
. . .
by stabilising the temperature [2013-01]
H03D 2200/0098
. . .
by compensating temperature induced variations [2013-01]