WIDEBAND DIGITAL FREQUENCY DISCRIMINATOR AND PHASE AND FREQUENCY DETECTOR

摘要

47WIDEBAND DIGITAL FREQUENCY DISCRIMINATORAND PHASE AND FREQUENCY DETECTORABSTRACTA wideband digital discriminator for demodulatingan FM signal is disclosed. An incoming FM signal cycles acounter through a series of sequential nonambiuouscyclical states A timer is provided for producing areference signal having a known relationship to the centerfrequency of the FM signal. First and second latches,synchronous with the timing means, are provided forsampling and storing information about the present andimmediately preceding output states of the counter. Adetector, operated synchronously with the referencesignal, detects differences in magnitude and directionbetween the present and immediately preceding sampledstates of the counter and generates an output signal whena state difference is detected. The output signal can bedigitally processed or integrated over time to provide ananalog discriminator output.