Design of an S band narrow-band bandpass BAW Filter

摘要

An S band narrowband bandpass filter BAW with center frequency 2.460 GHz, bandwidth 41 MHz, band insertion loss -1.154 dB. the passband ripple 0.9 dB, the out of band rejection about -42.5dB@2.385 GHz; -45.5dB@2.506 GHz was designed for potential UAV measurement and control applications. According to the design specifications, the design is as follows: each FBAR's stack was designed in BAW filter by using Mason model. Each FBAR's shape was designed with the method of apodization electrode. The layout of BAW filter was designed. The acoustic-electromagnetic co-simulation model was built to validate the performance of the designed BAW filter. The presented design procedure is a common one, and there are two characteristics: 1) an A&EM co-simulation method is used for the final BAW filter performance validation in the design stage, thus ensures over-optimistic designs by the bare ID Mason model are found and rejected in time; 2) An in-house developed auto-layout method is used to get compact BAW filter layout, which simplifies iterative error-and-try work here and output necessary in-plane geometry information to the A&EM co-simulation model.