Low Loss Surface-Acoustic-Wave Filters

For several years surface-acoustic-wave (SAW) devices have looked promising as future components for receiver front-end and intermediate frequency filters. However, high insertion loss and a time domain triple transit signal have limited the utilization of these devices. The low loss SAW filter overcomes both previous problems and is a milestone in electronic component development. Filters with loss as low as -0.6 dB at 35 MHz, -2.3 dB at 320 MHz, and -50 dB sidelobes are routinely constructed. This paper discusses surface-wave filters in general, and then specifically the design of low loss SAW filters.