A Fast Thermo-Piezoelectric Finite Element Model of 3D Transient FBAR Dynamics Under Large RF Signal

摘要

As high power RF filtering applications become increasingly relevant, there is a need to quickly predict the effect of nonlinear interactions between thermal and piezoelectric fields. Yet, traditional finite element methods (FEM) for 3D piezoelectric resonators impose unreasonable memory and time requirements. Here, we develop a fast finite element model of thermo-piezoelectric physics based on a generalized series expansion of the governing equations. Together with transient, thermal IR measurements of film bulk acoustic resonator (FBAR) under large signal, the model is used to explain a range of nonlinear phenomena reported here for the first time.