New SAW device substrate for synthetic aperture radar

Abstract

This paper presents an outline of a coherent pulse compression-expansion system constructed for an airborne synthetic aperture radar (SAR). The design concept, system performance, and experimental results are presented. Notably, a pair of conjugate surface acoustic wave (SAW) dispersive delay lines is implemented on a Bi12GeO20 substrate for the first time. The Bi12GeO20 substrate is chosen as a good tradeoff between insertion loss and temperature stability. Furthermore, its low acoustic velocity provides the added advantage of being able to use a shorter line to achieve the same time delay.