Analysis of surface acoustic wave resonators with boundary element method

The paper introduces a rigorous numerical model to analyze SAW (surface acoustic wave) resonators by BEM (boundary element method). At first it is proposed that the mass-loading effect of electrode is neglected and the surface of substrate is free, and the substrate is semi-infinite. Then corresponding programs are developed to analyze a SAW resonator. Electrical charge distribution on the electrode-substrate interface is expanded with Chebyshev polynomials in order to accelerate programs. Numerical results indicate that its admittance has good agreement with the result by FEM (finite element method) software ANSYS. Therefore BEM is a practical method to analyze SAW devices, which furthermore supports arbitrary electrode geometries and takes account of the effect of bulk wave.