Fast, Accurate and Full Extraction of Coupling-of-Modes Parameters by Finite Element Method

Abstract

This paper presents a new numerical approach for the full extraction of the coupling-of-modes (COM) parameters by stationary and eigenfrequency analyses in the finite element method (FEM). This is a fast method extracting from the results of static analysis and eigenfrequency analysis. It avoids the long calculation time of admittance frequency response analysis, which is commonly used in extracting COM parameters. In addition to the usual COM parameters (velocity, reflection coefficient, transduction coefficient and capacitance), the phases of reflection and transduction coefficient can be also extracted with this method. The proposed method was applied to different cutting types LiNbO3 with different types of thicknesses in a varying interdigital transducer (IDT). These examples show that our approach has great potential in extracting all the COM parameters of the Rayleigh SAW for all kinds of IDT structures. Therefore, it is a fast, accurate, general and full extraction approach of COM parameters.