Numerical simulation and comparison of membrane and solidly mounted FBAR´s

With the increase in operating frequencies of new wireless communication standards, Surface Acoustic Wave (SAW) devices are now facing competitors, such as thin film bulk acoustic resonators (FBARs). FBAR components are expected to overcome some of the limits of SAW components, and to provide miniature, high-performance and high-frequency filters. In this paper, we compare single resonator responses to more realistic configurations:a piezoelectric layer with relatively thick electrodes and a Solidly Mounted Resonator (SMR) with an acoustic mirror, and a resonator supported by a membrane. We then discuss how to adjust the relative thickness of the piezoelectric layer and of the electrodes to comply with frequency requirements for filtering applications.