A Novel Method to Extract COM Parameters for SAW Based on FEM

Acoustic surface wave (SAW) devices have an irreplaceable role in modern mobile communication due to their excellent performance. It is important to analyze and design SAW devices accurately. Coupling-of-Modes theory (COM) and P-Matrix are common methods to simulate the frequency response of SAW devices. Finite element method (FEM) is also an effective method to solve piezoelectric devices. It is very meaningful to combine these methods to improve the speed and accuracy of calculation. In order to extract COM parameters, an effective connection between admittance obtained by P-matrix and FEM basing on COM equation and P-Matrix was established. COM parameters are extracted by modal and harmonic analyses in FEM. The admittances result from COM with these COM parameters agree well with that from FEM in a wide frequency range. It illustrates the effectiveness of the novel method.