Improvement of methods in analyzing the propagation of plate waves in FBARs

This paper investigates and compares three methods for the analysis of the thin film bulk acoustic resonator (FBAR) in order to study the propagation of plate waves in the device. The finite element method (FEM) is compared to the Transfer Matrix (TM) and Global Matrix (GM) techniques, which are carefully modified in order to take into account the mixed-multilayer structure of the resonator. To the best of the authors' knowledge, the electrodes and the piezoelectric layer both are treated as layers with fully defined mechanical and electrical properties for the first time.