Design, Manufacture and Testing of Surface Acoustic Wave Filters

摘要

The design and implementation of surface acoustic wave bandpass filters with state-of-the-art selectivity for use in communications satellites are described. Designs in the range 350 to 400 MHz are discussed and the sensitivity of the devices to implementation errors, particularly mask defects, is illustrated. Measures to obtain improved masks are given, and equivalent designs at 200 MHz are described and shown to be considerably more tolerant to implementation errors than the higher frequency filters. The 200 MHz filters offer exceptional performance, and a pair of devices were delivered to ESA.