FEM modeling and simulation of a layered SAW device based on ZnO/128° YX LiNbO<inf>3</inf>

In this paper, the modeling and simulation of a layered surface acoustic wave device based on ZnO/128° YX LiNbO ₃ were conducted using Finite Element Method (FEM) in COMSOL Multiphysics 4.3b platform. The SAWs propagation characteristics were numerically investigated with variation in the ZnO layer thickness. The results show that the SAW device frequency response was varied with the ZnO layer thickness from 166.1 MHz to 150.4 MHz. The free and metalized phase velocities (ν _f and ν _m ) were calculated and used to calculate the electromechanical coupling coefficient (K ² ) of the structure. The results show that a large coupling coefficient of 6.05% can be obtained in 500 nm ZnO layer thickness which is in a good agreement with the data published by Nakamura and Hanamoka.