1. CPC Sections
  2. CPC Section H
  3. CPC Class H03
  4. CPC Subclass H03G
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Version: 2024.01
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CPC
COOPERATIVE PATENT CLASSIFICATION
​​
H03G
CONTROL OF AMPLIFICATION [2024-01]
NOTES

  • This subclass covers:
    • control of gain of amplifiers or frequency-changers;
    • control of frequency range of amplifiers;
    • limiting amplitude or rate of change of amplitude.
  • Attention is drawn to the Note following the title of subclass H03F.
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.
H03G 1/00
Details of arrangements for controlling amplification [2024-01]
H03G 1/0005
.
{Circuits characterised by the type of controlling devices operated by a controlling current or voltage signal} [2013-01]
H03G 1/0011
. .
{the device being at least one of the amplifying tubes of the amplifier} [2013-01]
H03G 1/0017
. .
{the device being at least one of the amplifying solid state elements of the amplifier} [2013-01]
H03G 1/0023
. . .
{in emitter-coupled or cascode amplifiers (H03G 1/0029 takes precedence)} [2015-07]
H03G 1/0029
. . .
{using FETs} [2013-01]
H03G 1/0035
. .
{using continuously variable impedance elements} [2013-01]
H03G 1/0041
. . .
{using thermistors} [2013-01]
H03G 1/0047
. . .
{using photo-electric elements} [2013-01]
H03G 1/0052
. . .
{using diodes} [2013-01]
H03G 1/0058
. . . .
{PIN-diodes} [2013-01]
H03G 1/0064
. . . .
{Variable capacitance diodes} [2013-01]
H03G 1/007
. . .
{using FET type devices} [2013-01]
H03G 1/0076
. . .
{using galvanomagnetic elements} [2013-01]
H03G 1/0082
. . .
{using bipolar transistor-type devices} [2013-01]
H03G 1/0088
. .
{using discontinuously variable devices, e.g. switch-operated} [2013-01]
H03G 1/0094
. . .
{using switched capacitors} [2013-01]
H03G 1/02
.
Remote control of amplification, tone or bandwidth (combined with remote tuning or selection of resonant circuits H03J) [2024-01]
H03G 1/04
.
Modifications of control circuit to reduce distortion caused by control (modifications to reduce influence of variations of internal impedance of amplifying elements caused by control H03F 1/08) [2013-01]
H03G 3/00
Gain control in amplifiers or frequency changers [2024-01]
H03G 3/001
.
{Digital control of analog signals} [2013-01]
H03G 3/002
.
{Control of digital or coded signals (H03G 3/3089 take precedence)} [2013-01]
H03G 3/004
.
{Control by varying the supply voltage} [2013-01]
H03G 3/005
.
{Control by a pilot signal (H03G 3/001 takes precedence)} [2013-01]
H03G 3/007
.
{Control dependent on the supply voltage} [2013-01]
H03G 3/008
.
{Control by switched capacitors} [2013-01]
H03G 3/02
.
Manually-operated control {(H03G 3/001 and H03G 3/002 take precedence)} [2013-01]
H03G 3/04
. .
in untuned amplifiers [2013-01]
H03G 3/06
. . .
having discharge tubes [2013-01]
H03G 3/08
. . . .
incorporating negative feedback [2013-01]
H03G 3/10
. . .
having semiconductor devices [2013-01]
H03G 3/12
. . . .
incorporating negative feedback [2013-01]
H03G 3/14
. .
in frequency-selective amplifiers [2013-01]
H03G 3/16
. . .
having discharge tubes [2013-01]
H03G 3/18
. . .
having semiconductor devices [2013-01]
H03G 3/20
.
Automatic control ({H03G 3/005 takes precedence;} combined with volume compression or expansion H03G 7/00) [2024-01]
H03G 3/22
. .
in amplifiers having discharge tubes [2013-01]
H03G 3/225
. . .
{controlling or controlled by the (local) oscillators of a (super)heterodyne receiver} [2013-01]
H03G 3/24
. . .
Control dependent upon ambient noise level or sound level [2013-01]
H03G 3/26
. . .
Muting amplifier when no signal is present {or when only weak signals are present, or caused by the presence of noise, e.g. squelch systems} [2013-01]
H03G 3/28
. . . .
in frequency-modulation receivers {; in angle-modulation receivers} [2017-08]
H03G 3/30
. .
in amplifiers having semiconductor devices [2013-01]
H03G 3/3005
. . .
{in amplifiers suitable for low-frequencies, e.g. audio amplifiers (H03G 3/32, H03G 3/34 take precedence)} [2013-01]
H03G 3/301
. . . .
{the gain being continuously variable} [2013-01]
H03G 3/3015
. . . . .
{using diodes or transistors} [2013-01]
H03G 3/3021
. . . . .
{by varying the duty cycle} [2013-01]
H03G 3/3026
. . . .
{the gain being discontinuously variable, e.g. controlled by switching} [2013-01]
H03G 3/3031
. . . . .
{using switched capacitors} [2013-01]
H03G 3/3036
. . .
{in high-frequency amplifiers or in frequency-changers (H03G 3/3052, H03G 3/32, H03G 3/34 take precedence)} [2013-01]
H03G 3/3042
. . . .
{in modulators, frequency-changers, transmitters or power amplifiers (transmission power control in bidirectional transmission systems H04W 52/04)} [2013-01]
H03G 3/3047
. . . . .
{for intermittent signals, e.g. burst signals} [2013-01]
H03G 3/3052
. . .
{in bandpass amplifiers (H.F. or I.F.) or in frequency-changers used in a (super)heterodyne receiver (H03G 3/32, H03G 3/34 take precedence)} [2013-01]
H03G 3/3057
. . . .
{using at least one diode as controlling device} [2013-01]
H03G 3/3063
. . . .
{using at least one transistor as controlling device, the transistor being used as a variable impedance device} [2013-01]
H03G 3/3068
. . . .
{Circuits generating control signals for both R.F. and I.F. stages} [2013-01]
H03G 3/3073
. . . .
{Circuits generating control signals when no carrier is present, or in SSB, CW or pulse receivers} [2013-01]
H03G 3/3078
. . . .
{Circuits generating control signals for digitally modulated signals} [2013-01]
H03G 3/3084
. . .
{in receivers or transmitters for electromagnetic waves other than radiowaves, e.g. lightwaves (H03G 3/32, H03G 3/34 take precedence)} [2013-01]
H03G 3/3089
. . .
{Control of digital or coded signals} [2013-01]
H03G 3/3094
. . .
{in parametric amplifiers (H03G 3/32, H03G 3/34 take precedence)} [2013-01]
H03G 3/32
. . .
the control being dependent upon ambient noise level or sound level [2013-01]
H03G 3/34
. . .
Muting amplifier when no signal is present {or when only weak signals are present, or caused by the presence of noise signals, e.g. squelch systems} [2013-01]
H03G 3/341
. . . .
{Muting when no signals or only weak signals are present (H03G 3/344, H03G 3/345 take precedence)} [2013-01]
H03G 3/342
. . . .
{Muting when some special characteristic of the signal is sensed which distinguishes it from noise, e.g. using speech detector (H03G 3/344, H03G 3/345 take precedence)} [2013-01]
H03G 3/344
. . . .
{Muting responsive to the amount of noise (noise squelch) (H03G 3/345 takes precedence)} [2013-01]
H03G 3/345
. . . .
{Muting during a short period of time when noise pulses are detected, i.e. blanking (H03G 3/348 takes precedence)} [2013-01]
H03G 3/347
. . . . .
{dependent on the rate of noise pulses} [2013-01]
H03G 3/348
. . . .
{Muting in response to a mechanical action or to power supply variations, e.g. during tuning; Click removal circuits} [2013-01]
H03G 5/00
Tone control or bandwidth control in amplifiers [2013-01]
H03G 5/005
.
{of digital signals} [2024-01]
H03G 5/02
.
Manually-operated control [2024-01]
H03G 5/025
. .
{Equalizers; Volume or gain control in limited frequency bands} [2013-01]
H03G 5/04
. .
in untuned amplifiers [2013-01]
H03G 5/06
. . .
having discharge tubes [2013-01]
H03G 5/08
. . . .
incorporating negative feedback [2013-01]
H03G 5/10
. . .
having semiconductor devices [2013-01]
H03G 5/12
. . . .
incorporating negative feedback [2013-01]
H03G 5/14
. .
in frequency-selective amplifiers [2013-01]
H03G 5/16
.
Automatic control [2013-01]
H03G 5/165
. .
{Equalizers; Volume or gain control in limited frequency bands} [2013-01]
H03G 5/18
. .
in untuned amplifiers [2013-01]
H03G 5/20
. . .
having discharge tubes [2013-01]
H03G 5/22
. . .
having semiconductor devices [2013-01]
H03G 5/24
. .
in frequency-selective amplifiers [2013-01]
H03G 5/26
. . .
having discharge tubes [2013-01]
H03G 5/28
. . .
having semiconductor devices [2013-01]
H03G 7/00
Volume compression or expansion in amplifiers {(frequency dependent H03G 9/00)} [2013-01]
H03G 7/001
.
{without controlling loop (H03G 7/007, H03G 7/02, H03G 7/06 take precedence)} [2013-01]
H03G 7/002
.
{in untuned or low-frequency amplifiers, e.g. audio amplifiers (H03G 7/007, H03G 7/001, H03G 7/008, H03G 7/02, H03G 7/06 take precedence)} [2016-08]
H03G 7/004
. .
{using continuously variable impedance devices} [2013-01]
H03G 7/005
. .
{using discontinuously variable devices, e.g. switch-operated} [2013-01]
H03G 7/007
.
{of digital or coded signals} [2024-01]
H03G 7/008
.
{Control by a pilot signal (H03G 7/007, H03G 7/02, H03G 7/06 take precedence)} [2013-01]
H03G 7/02
.
having discharge tubes [2013-01]
H03G 7/04
. .
incorporating negative feedback [2013-01]
H03G 7/06
.
having semiconductor devices [2013-01]
H03G 7/08
. .
incorporating negative feedback [2013-01]
H03G 9/00
Combinations of two or more types of control, e.g. gain control and tone control [2013-01]
H03G 9/005
.
{of digital or coded signals} [2015-07]
H03G 9/02
.
in untuned amplifiers [2024-01]
H03G 9/025
. .
{frequency-dependent volume compression or expansion, e.g. multiple-band systems (H03G 9/10, H03G 9/18 take precedence)} [2013-01]
H03G 9/04
. .
having discharge tubes [2013-01]
H03G 9/06
. . .
for gain control and tone control [2013-01]
H03G 9/08
. . . .
incorporating negative feedback [2013-01]
H03G 9/10
. . .
for tone control and volume expansion or compression [2013-01]
H03G 9/12
. .
having semiconductor devices [2013-01]
H03G 9/14
. . .
for gain control and tone control [2013-01]
H03G 9/16
. . . .
incorporating negative feedback [2013-01]
H03G 9/18
. . .
for tone control and volume expansion or compression [2013-01]
H03G 9/20
.
in frequency-selective amplifiers [2013-01]
H03G 9/22
. .
having discharge tubes [2013-01]
H03G 9/24
. .
having semiconductor devices [2013-01]
H03G 9/26
.
in untuned amplifying stages as well as in frequency-selective amplifying stages [2024-01]
H03G 9/28
. .
all amplifying stages having discharge tubes [2013-01]
H03G 9/30
. .
all amplifying stages having semiconductor devices [2013-01]
H03G 11/00
Limiting amplitude; Limiting rate of change of amplitude {; Clipping in general} [2017-08]
H03G 11/002
.
{without controlling loop (H03G 11/004, H03G 11/006, H03G 11/008, H03G 11/02, H03G 11/04, H03G 11/06, H03G 11/08 take precedence)} [2024-01]
H03G 11/004
.
{using discharge tubes (H03G 11/008 takes precedence)} [2013-01]
H03G 11/006
.
{in circuits having distributed constants (H03G 11/008 takes precedence)} [2013-01]
H03G 11/008
.
{of digital or coded signals} [2024-01]
H03G 11/02
.
by means of diodes ({H03G 11/008, } H03G 11/04, H03G 11/06, H03G 11/08 take precedence) [2013-01]
H03G 11/025
. .
{in circuits having distributed constants} [2013-01]
H03G 11/04
.
Limiting level dependent on strength of signal; Limiting level dependent on strength of carrier on which signal is modulated {(H03G 11/008 takes precedence)} [2013-01]
H03G 11/06
.
Limiters of angle-modulated signals; such limiters combined with discriminators (discriminators having an inherent limiting action H03D 3/00) [2024-01]
H03G 11/08
.
Limiting rate of change of amplitude {(H03G 11/008 takes precedence)} [2013-01]
H03G 99/00
Subject matter not provided for in other groups of this subclass [2013-01]
H03G 2201/00
Indexing scheme relating to subclass H03G [2013-01]
H03G 2201/10
.
Gain control characterised by the type of controlled element [2013-01]
H03G 2201/103
. .
being an amplifying element [2013-01]
H03G 2201/106
. .
being attenuating element [2013-01]
H03G 2201/20
.
Gain control characterized by the position of the detection [2013-01]
H03G 2201/202
. .
being in baseband [2013-01]
H03G 2201/204
. .
being in intermediate frequency [2013-01]
H03G 2201/206
. .
being in radio frequency [2013-01]
H03G 2201/208
. .
being in power supply of the amplifier [2013-01]
H03G 2201/30
.
Gain control characterized by the type of controlled signal [2013-01]
H03G 2201/302
. .
being baseband signal [2013-01]
H03G 2201/305
. .
being intermediate frequency signal [2013-01]
H03G 2201/307
. .
being radio frequency signal [2013-01]
H03G 2201/40
.
Combined gain and bias control [2013-01]
H03G 2201/50
.
Gain control characterized by the means of gain control [2013-01]
H03G 2201/502
. .
by switching impedance in feedback loop [2013-01]
H03G 2201/504
. .
by summing selected parallel amplifying paths, i.e. more amplifying/attenuating paths summed together [2013-01]
H03G 2201/506
. .
by selecting one parallel amplifying path [2013-01]
H03G 2201/508
. .
by using look-up tables [2013-01]
H03G 2201/60
.
Gain control characterized by varying time constants in control loop [2013-01]
H03G 2201/603
. .
time constant being continuous [2013-01]
H03G 2201/606
. .
time constant being discrete [2013-01]
H03G 2201/70
.
Gain control characterized by the gain control parameter [2013-01]
H03G 2201/702
. .
being frequency, e.g. frequency deviations [2013-01]
H03G 2201/704
. .
being number of multiplexed channels [2013-01]
H03G 2201/706
. .
being quality indicator, e.g. BER,C/I [2013-01]
H03G 2201/708
. .
being temperature [2013-01]