Modeling of RF filter component based on film bulk acoustic resonator

Abstract

Film bulk acoustic resonator (FBAR) is widely used as an individual component RF filter in RF circuit because of its very high Q factor and low temperature coefficient. However, the RF pads and bonding wires of FBAR component will lower its Q factor. This effect is modeled by a new model named as PMBVD based on the traditional modified Butterworth-Van Dyke (MBVD) model in this paper. PMBVD model can describe FBAR individual component more exactly than MBVD model, especially near FBAR operating frequency, as proved by test results. The influences by different kinds of RF pads are also analyzed based on PMBVD. The simulations based on PMBVD show that optimized RF pads can enhance whole device Q factor to meet demands.