Synchronous Integrator and Demodulator

Abstract

A demodulator system has been developed where integration is performed prior to demodulation. This allows a simple demodulator to be used to obtain a high level output with large dynamic range. A complete demodulator is described which gives a maximum dc output of 10V with an input rms signal‐to‐noise ratio as low as — 10 dB. The output zero drift is less than 50 μV/°C. The system is designed for radio astronomy applications, but is widely applicable for the recovery of signals ``buried'' in noise.