Accession Number : AD0438252


Title :   ACTIVE NOTCH FILTER.


Corporate Author : GEORGIA INST OF TECH ATLANTA ENGINEERING EXPERIMENT STATION


Report Date : Apr 1964


Pagination or Media Count : 56


Abstract : This report describes the theory of operation and the construction of a device to reject CW interference. The device constitutes a tunable, single frequency rejection filter which uses a phase locked oscillator to obtain a narrow rejection notch in the region of 455 kc. The notch response is obtained by cancelling the signal to be rejected with a locally generated signal of equal amplitude and opposite phase. Automatic phase and amplitude control of the cancellation signal permits the rejection notch to track slow frequency and amplitude changes in the signal being rejected. A notch width of less than 100 cps is obtained with tracking being maintained over a 10 kc bandwidth centered at 455 kc. (Author)


Descriptors :   RADIO INTERFERENCE , MEDIUM FREQUENCY , PHASE CONTROL , PHASE


Distribution Statement : APPROVED FOR PUBLIC RELEASE