Simulation of finite acoustic resonators from Finite Element Analysis based on mixed Boundary Element Method/Perfectly Matched Layer

Abstract

The simulation of finite length Surface Acoustic Wave (SAW) resonators is addressed here. Both the electro-mechanical coupling and the acoustic wave propagation in inhomogeneous space are considered through a Finite Element Analysis (FEA). The homogeneous parts of the space are treated using a Boundary Element Method (BEM) whereas the side edges of the transducer are completed by Perfectly Matched Layer (PML) method. By combining these two boundary methods BEM and PML, we are able to decrease the contributions of the losses due to the diffraction of SAW into Bulk Acoustic Waves (BAW). Thus, we can simulate the effects of real boundary filters (dual mode) on SAW resonators behavior as well as infinite passivation layer laid aver acoustic resonators.