H
SECTION H — ELECTRICITY
 H03
BASIC ELECTRONIC CIRCUITRY
 H03C
MODULATION (measuring, testing G01R; masers, lasers H01S; modulators specially adapted for use in dc amplifiers H03F 3/38; modulating pulses H03K 7/00; so-called modulators capable only of 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)
 H03C

Note(s)

  1. This subclass covers only modulation, keying, or interruption of sinusoidal oscillations or electromagnetic waves, the modulating signal having any desired waveform.
  2. In this subclass, circuits usable both as modulator and demodulator are classified in the group dealing with the type of modulator involved.
 H03C 1/00
Amplitude modulation (H03C 5/00, H03C 7/00 take precedence)
 H03C 1/02
·  Details
 H03C 1/04
·  ·  Means in, or combined with, modulating stage for reducing angle modulation
 H03C 1/06
·  ·  Modifications of modulator to reduce distortion, e.g. by feedback, and clearly applicable to more than one type of modulator
 H03C 1/08
·  by means of variable impedance element (H03C 1/28-H03C 1/34, H03C 1/46-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
 H03C 1/16
·  by means of discharge device having at least three electrodes (H03C 1/28-H03C 1/34, H03C 1/50, H03C 1/52, H03C 1/62 take precedence)
 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
 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
 H03C 1/36
·  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 1/38
·  ·  carrier applied to base of a transistor
 H03C 1/40
·  ·  ·  modulating signal applied to collector
 H03C 1/42
·  ·  ·  modulating signal applied to base
 H03C 1/44
·  ·  ·  modulating signal applied to emitter
 H03C 1/46
·  Modulators with mechanically- or acoustically-driven parts
 H03C 1/48
·  by means of Hall-effect devices
 H03C 1/50
·  by converting angle modulation to amplitude modulation (H03C 1/28-H03C 1/34, H03C 1/46, H03C 1/48 take precedence)
 H03C 1/52
·  Modulators in which carrier or one sideband is wholly or partially suppressed (H03C 1/28-H03C 1/34, H03C 1/46, H03C 1/48 take precedence)
 H03C 1/54
·  ·  Balanced modulators, e.g. bridge type, ring type, double balanced type
 H03C 1/56
·  ·  ·  comprising variable two-pole elements only
 H03C 1/58
·  ·  ·  ·  comprising diodes
 H03C 1/60
·  ·  with one sideband wholly or partially suppressed
 H03C 1/62
·  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-H03C 1/34, H03C 1/46, H03C 1/48 take precedence)
 H03C 3/00
Angle modulation (H03C 5/00, H03C 7/00 take precedence)
 H03C 3/02
·  Details
 H03C 3/04
·  ·  Means in, or combined with, modulating stage for reducing amplitude modulation
 H03C 3/06
·  ·  Means for changing frequency deviation
 H03C 3/08
·  ·  Modifications of modulator to linearise modulation, e.g. by feedback, and clearly applicable to more than one type of modulator
 H03C 3/09
·  ·  Modifications of modulator for regulating the mean frequency  [3]
 H03C 3/10
·  by means of variable impedance (H03C 3/30-H03C 3/38 take precedence)
 H03C 3/12
·  ·  by means of a variable reactive element
 H03C 3/14
·  ·  ·  simulated by circuit comprising active element with at least three electrodes, e.g. reactance-tube circuit
 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
 H03C 3/22
·  ·  ·  the element being a semiconductor diode, e.g. varicap diode
 H03C 3/24
·  ·  by means of a variable resistive element, e.g. tube
 H03C 3/26
·  ·  ·  comprising two elements controlled in push-pull by modulating signal
 H03C 3/28
·  ·  using variable impedance driven mechanically or acoustically
 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
 H03C 3/38
·  by converting amplitude modulation to angle modulation
 H03C 3/40
·  ·  using two signal paths the outputs of which have a predetermined phase difference and at least one output being amplitude-modulated
 H03C 3/42
·  by means of electromechanical devices (H03C 3/28 takes precedence)  [3]
 H03C 5/00
Amplitude modulation and angle modulation produced simultaneously or at will by the same modulating signal (H03C 7/00 takes precedence)
 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
 H03C 7/00
Modulating electromagnetic waves (devices or arrangements for the modulation of light G02F 1/00; for generating oscillations H03B, H03K)
 H03C 7/02
·  in transmission line, waveguide, cavity resonator, or radiation field of aerial
 H03C 7/04
·  ·  Polarisation of transmitted wave being modulated