A novel approach to simulate low-loss surface acoustic wave devices using dispersive COM parameters

This paper describes a novel approach to extract dispersive coupling-of-modes (COM) parameters for simulating low-loss surface acoustic wave (SAW) devices. A finite periodic grating is in consideration. Using finite FEM/BEM tool, the field (mechanical displacements and electric potential) distributions could be calculated at every frequency. Then the field contributed by SAW should be separated from the total field by Source Regeneration Method. Considering both short-circuited and open-circuited gratings, all the dispersive COM parameters can be evaluated. In particular, the dispersive reflection coefficient and propagation velocity are obtained independently. As an example, a synchronous one-port resonator is simulated using dispersive COM parameters extracted by the method mentioned in this paper. The electrical property of the resonator agrees well with the result simulated by finite FEM/BEM, which verifies this approach is accurate and effective.