Digital FM ratio detector with gain-controlled filter

Details Digital FM ratio detector with gain-controlled filter Digital FM ratio detector with gain-controlled filter

1983-04-25

1985-07-09

LaRoche, Eugene R.

Demodulators

Amplitude modulation demodulator

Having specific distortion, noise or other interference...

329130, 329132, 375 82, H03D 100

Patent

active

045285136

ABSTRACT:
A digital ratio detector for detecting digitized frequency-modulated (FM) signals develops sum and difference signals from input digital signals and from delayed representations thereof. The sum and difference signals are detected and further sum and difference signals are developed and are applied to respective lowpass digital filters having controllable gain. A gain control circuit develops a gain control signal which is applied to the digital lowpass filters to control the respective gains thereof so that the filtered digital signals produced by one of the digital filters includes digital representations of the deviations of the FM carrier.

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