Two-Dimensional Coupling-of-Modes Analysis in Surface Acoustic Wave Device Performed by COMSOL Multiphysics

Practical two-dimensional (2D) simulation is required in the analysis of surface acoustic wave (SAW) responses and in the design of SAW devices. As one of the 2D simulation methods, 2D coupling-of-modes (2D-COM) equations were adopted to analyze SAW behaviors on a surface plane. However, the method solving equations analytically lacks versatility and simplicity. In this paper, we propose a method that solves equations numerically by a finite element method (FEM) to realize high versatility. To verify the validity of this method, we carried out a 2D analysis for a two-port resonator by this method. An analysis model can be built simply by using a commercial FEM tool that can solve arbitrary equations. The simulation result obtained by this method is in good agreement with previous analytical and measured ones.