A review of SAW resonator filter technology

A compendium of design approaches that have proved to be successful in large-scale production of surface acoustic wave (SAW) resonators is provided. Many resonator configurations are presented and typical performance characteristics are illustrated. New developments are discussed. These include techniques for increasing coupled-resonator bandwidths<0.5% and weighting reflector banks to suppress close-in ripple. The trend towards high-coupling designs that do not require matching is also discussed, as are possible applications of new single-phase unidirectional transducer (SPUDT) technologies