An Analysis of Surface-Acoustic-Wave Devices on Layered Substrates

A unified approach based on the coupled mode theory and the finite-element method for the analysis of SAW devices on layered substrates is described. In this approach, all the parameters included in the coupled mode equations can be theoretically determined, and all of the effects of piezoelectric perturbation, mechanical perturbation, and energy storage due to evanescent bulk waves are taken into account. Examples are computed for various types of SAW gratings and one-port cavity resonators on layered substrates. The computed results approximately agree with the experimental results.