3D Modeling and Simulation of SH-SAW Devices Using the Finite Element Method

Abstract

Shear Horizontal Surface Acoustic Wave (SH-SAW) devices have been extensively used in chemical and biosensing applications mainly because these waves are not attenuated in liquid media like Rayleigh waves. It is extremely important to model and simulate the device prior to its actual fabrication in order to gain a better understanding of the device performance and optimizing its design parameters. This paper presents the 3-dimensional Finite Element (FE) modeling and simulation results for a SH-SAW device using CoventorWare TM (CW). The substrate used is 64˚ rotated Y-cut LiNbO 3 with Au/CrInterdigital Transducers (IDT) having a periodicity of 40 µm. 3D transient analysis was performed on the devices to study the acoustic wave propagation and characterize the device in timeand frequency domain. The normalized displacements at the output node are presented together with a 3D view of the SH-SAW wave propagation on the substrate. Also, a comparison is provided between the measured and simulated frequency response.

Development and experimental verification of a finite element method for accurate analysis of a surface acoustic wave device

“…Unlike other numerical methods, the FEM can model device characteristics using predefined boundary conditions, which make this method more versatile. Previous studies [21,22,[25][26][27] have reported an FEM analysis technique which utilized the voltage of the output IDT of a SAW device to predict its frequency response. The results indicated that three-dimensional (3D) FEM simulations were needed to accurately predict the frequency response of the fabricated device, however at the cost of using more computational resources than two-dimensional (2D) models [25,28,29].…”