|  | H |
SECTION H — ELECTRICITY

|  | H03 |
BASIC ELECTRONIC CIRCUITRY

|  | H03D |
DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TO ANOTHER (masers, lasers Fulltext... Hierarchy... Expanded...H01S; circuits capable of acting both as modulator and demodulator Fulltext... Hierarchy... Expanded...H03C; details applicable to both modulators and frequency-changers Fulltext... Hierarchy... Expanded...H03C; demodulating pulses Fulltext... Hierarchy... Expanded...H03K 9/00; transforming types of pulse modulation Fulltext... Hierarchy... Expanded...H03K 11/00; pulse code modulation Fulltext... Hierarchy... Expanded...H03K 13/00; repeater stations Fulltext... Hierarchy... Expanded...H04B 7/14; demodulators adapted for ac systems of digital-information transmission Fulltext... Hierarchy... Expanded...H04L 27/00; synchronous demodulators adapted for colour television Fulltext... Hierarchy... Expanded...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 (Fulltext... Hierarchy... Expanded...H03D 5/00, Fulltext... Hierarchy... Expanded...H03D 9/00, Fulltext... Hierarchy... Expanded...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 (Fulltext... Hierarchy... Expanded...H03D 1/22, Fulltext... Hierarchy... Expanded...H03D 1/26, Fulltext... Hierarchy... Expanded...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 (Fulltext... Hierarchy... Expanded...H03D 1/22, Fulltext... Hierarchy... Expanded...H03D 1/26, Fulltext... Hierarchy... Expanded...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 (Fulltext... Hierarchy... Expanded...H03D 1/26 takes precedence)

|  | H03D 3/00 |
Demodulation of angle-modulated oscillations (Fulltext... Hierarchy... Expanded...H03D 5/00, Fulltext... Hierarchy... Expanded...H03D 9/00, Fulltext... Hierarchy... Expanded...H03D 11/00 take precedence)

|  | H03D 3/02 |
· | by detecting phase difference between two signals obtained from input signal (Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...H03D 3/28-H03D 3/32 take precedence; limiting arrangements Fulltext... Hierarchy... Expanded...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 (Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...H03D 3/28-H03D 3/32 take precedence)

|  | H03D 3/28 |
· | Modifications of demodulators to reduce effect of temperature variations (automatic frequency control Fulltext... Hierarchy... Expanded...H03L)

|  | H03D 3/30 |
· | by means of transit-time tubes

|  | H03D 3/32 |
· | by deflecting an electron beam in a discharge tube (Fulltext... Hierarchy... Expanded...H03D 3/30 takes precedence)

|  | H03D 3/34 |
· | by means of electromechanical devices (Fulltext... Hierarchy... Expanded...H03D 3/16 takes precedence) [3]

|  | H03D 5/00 |
Circuits for demodulating amplitude-modulated or angle-modulated oscillations at will (Fulltext... Hierarchy... Expanded...H03D 9/00, Fulltext... Hierarchy... Expanded...H03D 11/00 take precedence)

|  | H03D 7/00 |
Transference of modulation from one carrier to another, e.g. frequency-changing (Fulltext... Hierarchy... Expanded...H03D 9/00, Fulltext... Hierarchy... Expanded...H03D 11/00 take precedence; dielectric amplifiers, magnetic amplifiers, parametric amplifiers used as frequency-changers Fulltext... Hierarchy... Expanded...H03F)

|  | H03D 7/02 |
· | by means of diodes (Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...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 (Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...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 (Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...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 (Fulltext... Hierarchy... Expanded...H03D 7/20 takes precedence)

|  | H03D 9/00 |
Demodulation or transference of modulation of modulated electromagnetic waves (demodulating light, transferring modulation in light waves Fulltext... Hierarchy... Expanded...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