Analysis and Research of Piezoelectric Thin Film Bulk Acoustic Filter

With the continuous emergence of communication products, piezoelectric film bulk acoustic resonator (FBAR), as a new star in the RF filter market, which has attracted the attention of researchers. This paper established the FBAR filter model that based on the one-dimensional simulation model of FBAR, then the influence factors of the performance of the device are simulated. The simulation results show that the insertion loss and in-band ripple of the filter are smaller under the L-type connection mode; As the effective resonance area ratio of series and parallel FBARs increases, the out-of-band suppression of the filter increases gradually, the band insertion loss becomes worse, and the passband bandwidth decreases gradually; In the L-type connection mode, with the increase of cascade order, the filter's out-of-band suppression ability is obviously enhanced, and the insertion loss also increases to a certain extent.