(under subclass 606) Subject matter in which the system includes a reference signal of the same frequency as the carrier frequency and of a fixed phase which is used with means to compare it with the phase modulated signal to obtain the modulating wave.
SEE OR SEARCH THIS CLASS, SUBCLASS:
683, for servo systems with particular phase sensitive discriminators. Also, subclass 314, for motor speed control with electrical phase difference type detectors.
SEE OR SEARCH CLASS
324, Electricity: Measuring and Testing,
76.52+, and 76.77+ for measuring and testing systems which include phase comparison.
327, Miscellaneous Active Electrical Nonlinear Devices, Circuits, and Systems, 3+, for phase comparison of plural inputs.
329, Demodulators,
103, and 110 for phase demodulation, per se.
340, Communications: Electrical,
825.70, for phase responsive remote control systems.
