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

Volume

45

Issue

2

fYear

1996

fDate

4/1/1996 12:00:00 AM

Firstpage

413

Lastpage

416

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;

fLanguage

English

Journal_Title

Instrumentation and Measurement, IEEE Transactions on

Publisher

ieee

ISSN

0018-9456

Type

jour

DOI

10.1109/19.492757

Filename

492757