Accession Number : ADD008038

Title :   Coherent Frequency Shift Key Demodulator.

Descriptive Note : Patent,


Personal Author(s) : McCorkle,John W

Report Date : 18 Nov 1980

Pagination or Media Count : 9

Abstract : Disclosed is a frequency shift key demodulator for the coherent detection of both mark and space tones. Cross coupled phase locked loops lock onto and track the difference in frequency between translated mark and space tones. An additional set of cross coupled phase locked loops locks onto and tracks overall frequency drift of the mark and space tones. Signals are generated within the first set of cross coupled loops allowing for coherent detection thereby permitting detection during signal to noise ratios of less than one. Loop bandwidths can be independently controlled and are independent of the data rate thus permitting wide system flexibility.

Descriptors :   *Patents, *Frequency shift keyers, *Demodulators, Coherence, Phase locked systems, Detection, Signal processing, Doppler effect, Signal to noise ratio, Decoders, Schematic diagrams, Drift, Waveforms

Subject Categories : Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE