H
SECTION H — ELECTRICITY
 H03
BASIC ELECTRONIC CIRCUITRY
 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; pulse code modulation H03K 13/00; repeater stations H04B 7/14; demodulators adapted for ac systems of digital-information transmission H04L 27/00; synchronous demodulators adapted for colour television H04N 9/50)
 H03D

Note(s)

This sub-class deals only with (a) demodulation or transference of signals modulated on a sinusoidal carrier or on electromagnetic waves, and (b) comparing phase or frequency of two mutually-independent oscillations.

 H03D 1/00
Demodulation of amplitude-modulated oscillations (H03D 5/00, H03D 9/00, H03D 11/00 take precedence)
 H03D 1/02
·  Details
 H03D 1/04
·  ·  Modifications of demodulators to reduce interference by undesired signals
 H03D 1/06
·  ·  Modifications of demodulators to reduce distortion, e.g. by negative feedback
 H03D 1/08
·  by means of non-linear two-pole elements (H03D 1/22, H03D 1/26, H03D 1/28 take precedence)
 H03D 1/10
·  ·  of diodes
 H03D 1/12
·  ·  ·  with provision for equalising ac and dc loads
 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)
 H03D 1/16
·  ·  of discharge tubes
 H03D 1/18
·  ·  of semiconductor devices
 H03D 1/20
·  ·  with provision for preventing undesired type of demodulation, e.g. preventing anode detection in a grid detection circuit
 H03D 1/22
·  Homodyne or synchrodyne circuits
 H03D 1/24
·  ·  for demodulation of signals wherein one sideband or the carrier has been wholly or partially suppressed
 H03D 1/26
·  by means of transit-time tubes
 H03D 1/28
·  by deflecting an electron beam in a discharge tube (H03D 1/26 takes precedence)
 H03D 3/00
Demodulation of angle-modulated oscillations (H03D 5/00, H03D 9/00, H03D 11/00 take precedence)
 H03D 3/02
·  by detecting phase difference between two signals obtained from input signal (H03D 3/28-H03D 3/32 take precedence; limiting arrangements H03G 11/00)
 H03D 3/04
·  ·  by counting or integrating cycles of oscillations
 H03D 3/06
·  ·  by combining signals additively or in product demodulators
 H03D 3/08
·  ·  ·  by means of diodes, e.g. Foster-Seeley discriminator
 H03D 3/10
·  ·  ·  ·  in which the diodes are simultaneously conducting during the same half period of the signal, e.g. ratio detector
 H03D 3/12
·  ·  ·  by means of discharge tubes having more than two electrodes
 H03D 3/14
·  ·  ·  by means of semiconductor devices having more than two electrodes
 H03D 3/16
·  ·  ·  by means of electromechanical resonators
 H03D 3/18
·  ·  by means of synchronous gating arrangements
 H03D 3/20
·  ·  ·  producing pulses whose amplitude or duration depends on the phase difference
 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
 H03D 3/24
·  ·  Modifications of demodulators to reject or remove amplitude variations by means of locked-in oscillator circuits
 H03D 3/26
·  by means of sloping amplitude/frequency characteristic of tuned or reactive circuit (H03D 3/28-H03D 3/32 take precedence)
 H03D 3/28
·  Modifications of demodulators to reduce effect of temperature variations (automatic frequency control H03L)
 H03D 3/30
·  by means of transit-time tubes
 H03D 3/32
·  by deflecting an electron beam in a discharge tube (H03D 3/30 takes precedence)
 H03D 3/34
·  by means of electromechanical devices (H03D 3/16 takes precedence)  [3]
 H03D 5/00
Circuits for demodulating amplitude-modulated or angle-modulated oscillations at will (H03D 9/00, H03D 11/00 take precedence)
 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 frequency-changers H03F)
 H03D 7/02
·  by means of diodes (H03D 7/14-H03D 7/22 take precedence)
 H03D 7/04
·  ·  having negative resistance characteristic, e.g. tunnel diode
 H03D 7/06
·  by means of discharge tubes having more than two electrodes (H03D 7/14-H03D 7/22 take precedence)
 H03D 7/08
·  ·  the signals to be mixed being applied between the same two electrodes
 H03D 7/10
·  ·  the signals to be mixed being applied between different pairs of electrodes
 H03D 7/12
·  by means of semiconductor devices having more than two electrodes (H03D 7/14-H03D 7/22 take precedence)
 H03D 7/14
·  Balanced arrangements
 H03D 7/16
·  Multiple frequency-changing
 H03D 7/18
·  Modifications of frequency-changers for eliminating image frequencies
 H03D 7/20
·  by means of transit-time tubes
 H03D 7/22
·  by deflecting an electron beam in a discharge tube (H03D 7/20 takes precedence)
 H03D 9/00
Demodulation or transference of modulation of modulated electromagnetic waves (demodulating light, transferring modulation in light waves G02F 2/00)
 H03D 9/02
·  Demodulation using distributed inductance and capacitance, e.g. in feeder lines
 H03D 9/04
·  ·  for angle-modulated oscillations
 H03D 9/06
·  Transference of modulation using distributed inductance and capacitance
 H03D 11/00
Super-regenerative demodulator circuits
 H03D 11/02
·  for amplitude-modulated oscillations
 H03D 11/04
·  ·  by means of semiconductor devices having more than two electrodes
 H03D 11/06
·  for angle-modulated oscillations
 H03D 11/08
·  ·  by means of semiconductor devices having more than two electrodes
 H03D 13/00
Circuits for comparing the phase or frequency of two mutually-independent oscillations