Application of the Finite Element Method for Calculating Parameters of Surface Acoustic Waves and Devices Based on Them

A series of models based on the finite element method (FEM) for analyzing the parameters of surface acoustic waves (SAWs) and devices based on them are described. The computer method for generating models in the COMSOL Multiphysics program is described in a generalized form. The work in three main solvers in the COMSOL environment—the stationary mode, eigenfrequency domain, and frequency domain—is described and graphically illustrated. The properties of Rayleigh waves and leaky SAWs are analyzed. A visualization of a number of characteristics is presented. The analysis of parameters such as the phase velocity of the wave, electromechanical coupling coefficient, and static capacitance of the transducer is considered. The examples consider an equidistant transducer, a transducer with split electrodes, and a unidirectional transducer of the DART type. Methods for analyzing harmonics in SAWs and the waveguide effect are proposed. It is shown that the model is valid for both single-crystal substrates and layered structures. The analysis of the temperature coefficient of the frequency for structures as such TCSAW (temperature-compensated SAW) and I.H.P.SAW (incredible high-performance SAW) is considered. A model for calculating the amplitude-frequency responses of devices is presented. It is shown that the data obtained as a result of the numerical analysis correspond to the experimental data and known published sources.