A uniformly-sampled single-phase unidirectional transducer with sub-Nyquist spatial sampling

A new family of surface acoustic wave (SAW) transducers based on unique sampling rates is introduced. Among these is a new single-phase unidirectional transducer (SPUDT) that has significant advantages over existing configurations. The new SPUDT is uniformly sampled with constant-width electrodes. It has better coupling than existing SPUDTs. Good distributed reflectivity can be achieved. Transduction and reflection functions are implemented independently. In-phase and quadrature taps can be implemented for both the transduction and reflection functions. Asymmetric frequency responses can be implemented or matching distortion effects compensated without chirping the transducer. The new SPUDT can be made unidirectional on arbitrary crystal orientations. The critical geometry is relatively large, enabling the transducer to be built at frequencies over 1 GHz