A New Method to Reconfigure BAW-SMR Filters Using CMOS Transistors

This paper presents a new method to reconfigure the bulk acoustic wave (BAW) filters by adding inductors to the shunt resonators and by controlling these inductors with CMOS transistors that act as switches. We show an application of this new technique to a filter designed for the WLAN-802.11 b/g standard (2400-2480 MHz). In a first step, the filter design was realized for implementation in a SiP context to validate our architecture and to evaluate the potential of this new method. Applying this technique enables us to increase approximately 32% the original bandwidth and to improve the out of band rejection.