Share Email Print

Proceedings Paper

Signal Processing With Acousto-Electric Surface Acoustic Wave (SAW) Devices
Author(s): I. Yao
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

Interest in acoustoelectric SAW devices has grown rapidly in the past few years. One of the reasons for this expansion is the potential capability of these devices to perform sophisticated real-time programmable signal processing. The essential ingredient in these devices is the acoustoelectric interaction of free carriers in a semiconductor with the evanescent RF electric fields accompanying surface acoustic waves (SAWs) propagating on a nearby piezoelectric substrate. Coupling of the electric fields from the piezoelectric to the semiconductor takes place across a narrow (-300 nm) air gap. The complexity of the semiconductor ranges from the simple distributed surface varactor of the convolver, to the high density diode array (few pm periodicity) of the acoustoelectric devices with charge storage, to the fully integrated microcircuit of the complex charged-coupled devices (SAW/CCD). The convolver provides, in a compact structure, matched filtering with a processing gain in excess of 30 dB and bandwidths up to 200-MHz for spread-spectrum waveforms, a function which would otherwise require a large digital machine operating at 1011 arithmetic operations per second. Other devices, newer than the convolver, are being explored which promise increasingly sophisticated signal processing capability. For instance, the memory correlator and the SAW/CCD programmable matched filter can be used in radar receivers in place of fixed matched filters to reduce the time spent in system alignment and to introduce programmability; the integrating correlator and the SAW/CCD accumulating correlator have the potential to be used in spread-spectrum systems for the correlation of very long (�msec) waveforms and the coherent integrator could provide a programmable burst-waveform processor for pulse-Doppler radar. As examples of the large variety of acoustoelectric SAW signal processors, three specific air-gap devices, the convolver, the memory correlator, and the coherent integrator will be described.

Paper Details

Date Published: 25 February 1981
PDF: 9 pages
Proc. SPIE 0239, Guided Wave Optical and Surface Acoustic Wave Devices: Systems and Applications, (25 February 1981); doi: 10.1117/12.959211
Show Author Affiliations
I. Yao, Massachusetts Institute of Technology (United States)

Published in SPIE Proceedings Vol. 0239:
Guided Wave Optical and Surface Acoustic Wave Devices: Systems and Applications
Chen S. Tsai, Editor(s)

© SPIE. Terms of Use
Back to Top