Abstract
The aim of this study is to characterize the wave propagation and to figure out the phase velocity and electromechanical coupling coefficient of a multi-layer piezoelectric substrate, which is used in surface acoustic wave (SAW) filters. To successfully estimate the values of the electromechanical coupling coefficients for bulk materials (single layer) and multi-layer structures, the effective surface permittivity (ESP) method was used. In order to analyze the ESP of a single layer, the material properties, such as stiffness tensor, piezoelectric stress tensor, permittivity tensor, and mass density are determined; while calculating the ESP of a multiple layer, the material properties are selected and transferred. The simulation results agree with the experimental results with the margin of error less than 7% for quartz in single layer. In analyzing the double layer materials; that is, ZnO/Diamond and LiNbO 3 /Diamond, K 2 number and phase velocity are obtained. For triple layers, the simulation are performed to demonstrate that ZnO/PZT/Diamond is a better substrate with 12000 m/s phase velocity and K 2 = 0.82. The results of this work demonstrate that numerical computations based on the chosen formalisms applied on non-piezoelectric film, diamond, are first brought out and benefit the researchers who wish to calculate surface acoustic wave properties in piezoelectric multi-layer structures.