Miniaturized BAW Filter for Wide Band Application based on High Q Factor Active Inductor

In this article, a wide band active inductor based on three common-source amplifiers constructed with N-type transistors is proposed. The simulation results show that the active inductor can operate at a frequency of 2-7GHz, with a variable inductance from 1nH to 10nH, and a quality factor up to 4K. The piezoelectric bulk wave resonator (BAW) filter is the main frequency selective device for 3-10GHz application and widely used in mobile communication, wifi and other fields. The BAW has high-Q but narrowband characteristics, so BAW needs to be integrated with IPD (integrated passive inductor) to achieve broadband filtering. However, The large size and mutual inductance of IPD severely limit the performance of filters, so this article proposes the replacement IPDs with active inductors and combined with BAW to achieve hybrid integration filter to Miniaturized BAW Filter, at same time maintain its performance.