Dynamic 2D analysis of SAW-devices including massloading

Abstract

A hybrid analysis-technique for the calculation of surface- and bulk-acoustic wave interaction with a periodic sequence of massive electrodes on a piezoelectric substrate is presented. The method combines the finite element method (FEM) and the boundary element method (BEM) and relies on Floquet's theorem, which employs a periodic Green's function. The massive electrodes are described by means of FEM. Interdigital transducers (IDTs) with electrodes characterized by single- and multiple-valued profile functions and anisotropic-inhomogeneous materials can be analyzed. To demonstrate the feasibility of the authors' method, two classes of problems are analyzed: (i) the excitation problem, where the charge- and stress-distribution on the electrode surfaces are calculated; and (ii) the Eigenstate problem, which leads to the dispersion diagram associated with electrically shorted or open massive Al- and Au-electrode arrays on LiNbO/sub 3/, LiTaO/sub 3/, and quartz.<>