A SAW resonator filter exploiting RMSCs

Reversing multistrip couplers are applied as reflecting structures in the double channel SAW resonator filter. The reflection is purely electrical. Double channel operation of the resonator is advantageous for many reasons, one is that the resonator performance does not depend on the position of interdigital transducers in the cavity region, the feature that otherwise can be obtained by using much more complicated unidirectional transducers. The theory of RMSC is presented based on spectral analysis of the field in a general structure with nonidentical acoustic channels (as in RMSC beam compressor). Scattering matrix is derived. Final relations for SAW resonator filter are presented as well as some experimental results, including that obtained for “chirp” dispersive RMSC