Application of the finite element method for calculating the surface acoustic wave parameters and devices

A series of models based on the finite element method (FEM) for analyzing the parameters of surface acoustic waves (SAW) and devices based on them are described. The computer method for generating models in the COMSOL Multiphysics is described. Three main studies in the COMSOL are described and graphically illustrated: stationary, eigenfrequency, frequency domain. The properties of Rayleigh waves and leaky SAW are analyzed. A visualization of a number of characteristics is presented. The analysis of such parameters as phase velocity of the wave, electromechanical coupling coefficient, and static capacitance of 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 SAW harmonics 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 frequency for such structures as TCSAW and I.H.P.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 numerical analysis correspond to experimental data and known literature sources.