Bulk acoustic wave devices and method for spurious mode suppression

摘要

A bulk acoustic wave resonator desirably suppressing spurious modes includes a frame-like structure of mass loading contacting one electrode, wherein the frame-like structure is defined within inner and outer boundaries and wherein a central area extends through the resonator within an envelope of the inner boundary and a border region extends through the resonator within the inner and outer boundaries of the frame-like structure. A second electrode is positioned within the envelope and substantially missing from within the border region. A layer of piezoelectric material is embedded between the first and second electrodes. An active resonator area is substantially within the central area. The resonator structure is carried on a substrate and an acoustically reflective mirror having multiple and alternating layers of low and high acoustic impedance material.