Accession Number : AD0164000

Title :   Automatic Frequency Control for Suppressed Carrier Receivers.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON D C

Personal Author(s) : Villard,Oswald G. , Jr

Report Date : 28 NOV 1972

Pagination or Media Count : 8

Abstract : The patent describes an automatic frequency control circuit for receivers of suppressed carrier SSB voice signals. First, the incoming signals are rectified in a conventional AM diode detector. The audio output, for vowels and voiced sounds, will consist primarily of the fundamental and harmonics of the vocal cord vibrations. This harmonic spectrum is then compared with the analogous voice harmonics at the output of a product detector. If the compared voice harmonics are mismatched in audio frequency, then an error signal is generated which is used to adjust the frequency of the locally generated carrier signal which is injected into the product detector. Frequency adjustment will continue until the error signal approaches zero and there is no voice harmonic frequency mismatch.

Descriptors :   (*AUTOMATIC FREQUENCY CONTROL, RADIO RECEIVERS), (*PATENTS, AUTOMATIC FREQUENCY CONTROL), SINGLE SIDEBAND COMMUNICATIONS

Subject Categories : Radio Communications

Distribution Statement : APPROVED FOR PUBLIC RELEASE