Project Echo: FM Demodulators with Negative Feedback
01 July 1961
FM Demodulators with Negative Feedback By CLYDE L. R U T H R O F F (Manuscript received M a r c h 22, 19(51) The FM receiving demodulators used in the Echo experiment are described in this paper. These receivers have negative feedback applied to the local oscillator to reduce the FM modulation index in the receiver intermediate frequency amplifiers. This technique results in a threshold performance which is superior to that of a conventional FM receiver.