Title :
A novel differential synchronous demodulator for AC signals
Author :
Pallás-Areny, Ramón ; Casas, Óscar
Author_Institution :
Dept. d´´Enginyeria Electron., Univ. Politecnica de Catalunya, Barcelona, Spain
fDate :
4/1/1996 12:00:00 AM
Abstract :
We describe a new analog differential synchronous demodulator for AC signals where (i) the signal is synchronously demodulated using the floating-capacitor technique after being amplified, if necessary, by an AC amplifier with differential input and differential output, thus yielding a very high CMRR; and (ii) the differential-to-single-ended signal conversion is performed after demodulation, that is, on a low-frequency signal that can be amplified by low-cost, high-performance circuits. The possible signal-to-noise ratio degradation because of synchronous sampling is prevented by using bandpass differential filters
Keywords :
band-pass filters; demodulators; differential amplifiers; low-pass filters; sample and hold circuits; signal sampling; switched capacitor filters; AC signals; amplitude demodulation; analog differential synchronous demodulator; bandpass differential filters; differential input; differential output; differential-to-single-ended signal conversion; floating-capacitor technique; low-cost high-performance circuits; quadrature rejection; sample and hold; signal-to-noise ratio degradation; synchronous sampling; very high CMRR; Bandwidth; Circuits; Demodulation; Detectors; Differential amplifiers; Frequency; Low pass filters; Sampling methods; Signal to noise ratio; Switches;
Journal_Title :
Instrumentation and Measurement, IEEE Transactions on
