Fast analysis of SAW propagation under multi-electrode-type gratings with finite thickness

Abstract

The paper proposes the method for the fast and accurate analysis of SAW propagation under metallic gratings consisting of multiple electrodes having unequal width, pitch and/or thickness: the grating structure is promising for developing single-phase unidirectional transducers (SPUDTs) with controlled passband shapes. The finite element method (FEM) is applied to the electroded region to take account of the effect of electrode thickness (mass-loading effect), and spectral domain analysis (SDA) to the substrate region for rapid computation. Electrical properties of the grating are determined by applying Aoki's theory to the results of FEM and SDA at the boundary. Two kinds of typical metallic gratings were analysed, and the unidirectionality was discussed for SPUDTs employing these grating structures.