The Design of Surface Acoustic Wave Receiving Circuit Based on Piezoelectric Transducer

摘要

A type of Surface Acoustic Wave (SAW) receiving circuit with high stability is introduced in this paper on the basis of analyzing common surface acoustic wave receiving circuits. The circuit design is based on receiving transducer and the center frequency is 1 MHz. This circuit includes pre-amplification electric circuit with high input impedance, automatic gain amplifying circuit based on VCA810, tertiary amplifying circuit, filter circuit and automatic voltage com-parison circuit. Receiving gate is used to preventing transmission pulse inter-feres the receipt signal. For better detecting the arrival time of receipt signal, volt age comparing circuit is served as examining the receipt signal, and meas-urement accuracy of acoustic transit time is improved substantially. By con-trast, amplification in three levels improves the circuit’s working stability. In addition, the circuit has the advantage of simple structure, signal stability and low manufacturing cost.