A Novel Offset-Compensated Low-Level Envelope Detector

An integrated envelope detector for the linear and accurate detection of amplitude modulated signals at levels as low as 3 mV and frequencies up to 15 MHz is presented. The DC input offset voltage is automatically compensated by using a novel technique. The circuit employs full-wave detection in an accurate biased diode bridge. At an 80% modulation depth, the distortion in the demodulated signal is well below 1%.