PIEZOELECTRIC FEM ANALYSIS OF SURFACE ACOUSTIC WAVE SENSOR

The paper is focused on modeling and simulation of surface acoustic wave devices using finite element method, especially by code ANSYS. SAW sensor is made of piezoelectric GaN layer, in which the Rayleigh waves are generated, and of SiC substrate. Full 3D model of SAW sensor is investigated, where mechanical material model of GaN is considered to be transversally isotropic. Two different analyses are performed: modal and full transient. Modal analysis is performed to determine the speed of the Rayleigh waves in piezoelectric material and also in order to determine the interdigital transducer eigenfrequency, which is used in next transient analysis as electric frequency of excitation. The second analysis is the transient analysis, where the goal is to compare voltage on input and output interdigital transducer as well as wave propagation delay.