Modern Physical-Mathematical Models and Methods for Design Surface Acoustic Wave Devices: COM Based P-Matrices and FEM in COMSOL

Abstract

Comparative results of calculation and measurement of the frequency responses of the surface acoustic waves filter on a piezoelectric substrate of 64°YX-cut lithium niobate and delay line on a piezoelectric substrate of 128°YX-cut lithium niobate is presented. The calculation was performed on the basis of two approaches—the finite element method in the COMSOL Multiphysics software and using the model of coupling of modes based on P-matrices. A brief overview and features of each approach are presented. The calculation results based on the two approaches are in good agreement with each other and with the experimental results of measurements of the characteristics of the bandpass filter. The delay line operating with the use of the third harmonic frequency is calculated by FEM. The results showed a good match between numerical simulation and experiment. The considered approaches for designing SAW devices allow us to relatively quickly and accurately predict the frequency responses at the simulation stage, thereby reducing the number of experimental iterations and increasing the efficiency of development.