IPC 6 English version H03F !A-H03F 21/00

H03F-H03F02100

SECTION H– ELECTRICITY

H 03

BASIC ELECTRONIC CIRCUITRY

H 03 F

AMPLIFIERS (measuring, testing G 01 R; optical parametric amplifiers G 02 F; circuit arrangements with secondary emission tubes H 01 J 43/30; masers, lasers H 01 S; control of amplification H 03 G; coupling arrangements independent of the nature of the amplifier, voltage dividers H 03 H; amplifiers capable only of dealing with pulses H 03 K; repeater circuits in transmission lines H 04 B 3/36, H 04 B 3/58; application of speech amplifiers in telephonic communication H 04 M 1/60, H 04 M 3/40)

Note

This subclass covers:

–

linear amplification, there being linear relationship between the amplitudes of input and output, and the output having substantially the same waveform as the input;

–

dielectric amplifiers, magnetic amplifiers, and parametric amplifiers when used as oscillators or frequency-changers;

–

constructions of active elements of dielectric amplifiers and parametric amplifiers if no provision exists elsewhere.

Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements

Modifications of amplifiers to raise the efficiency, e.g. gliding Class A stages, use of an auxiliary oscillation

in discharge-tube amplifiers

to raise the efficiency of amplifying modulated radio frequency waves; to raise the efficiency of amplifiers acting also as modulators [2]

Doherty-type amplifiers [2]

Modifications of amplifiers to reduce detrimental influences of internal impedances of amplifying elements (wide-band amplifiers with inter-stage coupling networks incorporating these impedances H 03 F 1/42; eliminating transit-time effects in vacuum tubes H 01 J 21/34)

by use of amplifying elements with multiple electrode connections

by use of attenuating means

in discharge-tube amplifiers [2]

by use of neutralising means

in discharge-tube amplifiers

by use of distributed coupling

in discharge-tube amplifiers

by use of cascode coupling, i.e. earthed cathode or emitter stage followed by earthed grid or base stage respectively

in discharge-tube amplifiers

Modifications of amplifiers to reduce influence of noise generated by amplifying elements

in discharge-tube amplifiers

Modifications of amplifiers to reduce influence of variations of temperature or supply voltage

Modifications of amplifiers to reduce non-linear distortion (by negative feedback H 03 F 1/34)

in discharge-tube amplifiers [2]

Negative-feedback-circuit arrangements with or without positive feedback (H 03 F 1/02 to H 03 F 1/30, H 03 F 1/38 to H 03 F 1/50, H 03 F 3/50 take precedence) [3]

in discharge-tube amplifiers

Positive-feedback circuit arrangements without negative feedback

in discharge-tube amplifiers

Modifications of amplifiers to extend the bandwidth

of tuned amplifiers

with tubes only

of aperiodic amplifiers

with tubes only

Circuit arrangements for protecting such amplifiers [3]

with tubes only [3]

Modifications of input or output impedances, not otherwise provided for [3]

Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements

Note

Groups H 03 F 3/20 to H 03 F 3/72 take precedence over groups H 03 F 3/02 to H 03 F 3/195. [2]

with tubes only (subsequent subgroups take precedence)

with semiconductor devices only (subsequent subgroups take precedence)

using hole storage effect

controlled by light

with diodes

with Esaki diodes

with amplifying devices having more than three electrodes or more than two PN junctions

with field-effect devices

with semiconductor devices of complementary types (subsequent subgroups take precedence)

181

Low-frequency amplifiers, e.g. audio preamplifiers [2]

183

with semiconductor devices only [2]

185

with field-effect devices (H 03 F 3/187 takes precedence) [2]

187

in integrated circuits [2]

189

High-frequency amplifiers, e.g. radio frequency amplifiers [2]

with semiconductor devices only [2]

191

Tuned amplifiers (H 03 F 3/193, H 03 F 3/195 take precedence) [2]

193

with field-effect devices (H 03 F 3/195 takes precedence) [2]

195

in integrated circuits [2]

Power amplifiers, e.g. Class B amplifiers, Class C amplifiers (H 03 F 3/26 to H 03 F 3/32 take precedence)

with semiconductor devices only [2]

213

in integrated circuits [2]

217

Class D power amplifiers; Switching amplifiers [2]

with tubes only (H 03 F 3/24 takes precedence)

of transmitter output stages

Push-pull amplifiers; Phase-splitters therefor (duplicated single-ended push-pull arrangements or phase-splitters therefor H 03 F 3/30)

with tubes only

Single-ended push-pull amplifiers; Phase-splitters therefor

with tubes only

Dc amplifiers in which all stages are dc-coupled (H 03 F 3/45 takes precedence) [3]

343

with semiconductor devices only [2]

345

with field-effect devices (H 03 F 3/347 takes precedence) [2]

347

in integrated circuits [2]

with tubes only

Dc amplifiers with modulator at input and demodulator at output; Modulators or demodulators specially adapted for use in such amplifiers (modulators in general H 03 C; demodulators in general H 03 D; amplitude modulation of pulses in general H 03 K 7/02; amplitude demodulation of pulses in general H 03 K 9/02)

387

with semiconductor devices only [2]

393

with field-effect devices [2]

with tubes only

Amplifiers with two or more amplifying elements having their dc paths in series with the load, the control electrode of each element being excited by at least part of the input signal, e.g. so-called totem-pole amplifiers

with tubes only

Differential amplifiers [2]

Reflex amplifiers

with tubes only

Amplifiers in which input is applied to, or output is derived from, an impedance common to input and output circuits of the amplifying element, e.g. cathode follower

with tubes only

Amplifiers using transit-time effect in tubes or semiconductor devices (parametric amplifiers H 03 F 7/00; solid state travelling-wave devices H 01 L 45/02)

with semiconductor devices only [2]

using klystrons

using travelling-wave tubes

Amplifiers in which coupling networks have distributed constants, e.g. with waveguide resonators (H 03 F 3/54 takes precedence)

Two-way amplifiers

with tubes only

Amplifiers simultaneously generating oscillations of one frequency and amplifying signals of another frequency

Combinations of amplifiers, e.g. multi-channel amplifiers for stereophonics

Charge amplifiers [2]

Gated amplifiers, i.e. amplifiers which are rendered operative or inoperative by means of a control signal [2]

Amplifiers with both discharge tubes and semiconductor devices as amplifying elements

Parametric amplifiers (devices or arrangements for the parametric generation or amplification of light, infra-red or ultra-violet waves G 02 F 1/39)

using variable-inductance element; using variable-permeability element

using variable-capacitance element; using variable-permittivity element

with electron beam tube

Magnetic amplifiers

current-controlled, i.e. the load current flowing in both directions through a main coil [2]

voltage-controlled, i.e. the load current flowing in only one direction through a main coil, e.g. Logan circuits (H 03 F 9/06 takes precedence) [2]

Control by voltage time integral, i.e. the load current flowing in only one direction through a main coil, whereby the main coil winding also can be used as a control winding, e.g. Ramey circuits [2]

11/

Dielectric amplifiers

13/

Amplifiers using amplifying element consisting of two mechanically- or acoustically-coupled transducers, e.g. telephone-microphone amplifier

15/

Amplifiers using galvano-magnetic effects not involving mechanical movement, e.g. using Hall effect

17/

Amplifiers using electroluminescent element or photocell

19/

Amplifiers using superconductivity effects

21/

Amplifiers not covered by groups H 03 F 3/00 to H 03 F 19/00 (dynamo-electric amplifiers H 02 K)