Full Wave Simulation and Design of Film Bulk Acoustic Wave Filters

Abstract

In order to simulate the frequency response of thin film bulk acoustic wave filter accurately, the MBVD model of film bulk acoustic wave filter chip and three dimension electro-magnetic model of package were respectively established. And then, the collaborative simulation of acoustic and electro-magnetic components was realized in ADS software. Finally, thin film bulk acoustic wave filter with working frequency of 2.825GHz and 5.6 GHz were designed and fabricated by this method. Insertion loss of 2.825GHz FBAR filter is less than 1.5dB, and rejection is more than 40dB. Insertion loss of 5.6GHz FBAR filter is less than 1.7dB, and rejection is more than 30dB. The simulation and experimental results show that the proposed method has good design precision and can simulate the influence of package on the performance of the filter accurately.