Finite element simulation and analysis of double-stepped film bulk acoustic resonator
To effectively suppress parasitic resonance in film bulk acoustic resonator(FBAR)and meet the high frequency requirement of 5G communication,two-dimensional and three-dimensional finite element models of the FBAR were established using Comsol Multiphysics software.Analysis was performed to understand the effect of piezoelectric materials,transverse electrode sizes and electrode shapes on the parasitic resonance of the FBAR.Furthermore,it discussed the impact of electrode frame structures on the quality factor(Qp)at the FBAR parallel resonant frequency(fp).Based on the analysis,a double-step electrode frame structured FBAR was proposed and designed.The FBAR utilizes AlN as the piezoelectric material,and it features a pentagonal electrode shape.The central frequency of the FBAR is 3.504 GHz with serial resonance frequency of 3.467 GHz,parallel resonance frequency of 3.541 GHz,and Qp value of 1591.Compared with the unoptimized one,the Qp value is improved by 19.2%,which effectively suppresses the parasitic resonance.
film bulk acoustic resonatorfinite element simulationparasitic resonanceresonant frequencydouble step structurequality factor