Abstract: A surface acoustic wave device for generating an output signal with only a symmetric or only an asymmetric vibration acoustic wave mode in a piezoelectric substrate. The device has first and second transversely spaced transducers and the device is driven from both the first and second transducers. A third transducer is between and acoustically coupled to the first two transducers. The electrodes of all three transducers are arranged with respect to each other so as to cause only a symmetrical acoustic vibration mode or only an asymmetrical acoustic vibration mode in the piezoelectric substrate.

Abstract: A surface acoustic wave resonator device having a resonant cavity formed on a substrate between a transducer and its related grating that causes a symmetric frequency response with one major resonant frequency response and low spurious frequency responses, with no etched grooves or recessed electrodes, with a minimum electrode geometry of .lambda./4, with single level fabrication and uniform wave velocity throughout the structure and being frequency insensitive to electrode reflections.