Patent ID: 8513863

Claim:
A piezoelectric resonator device, comprising: a top layer including one or more top layer metal electrodes, wherein in a first area, the top layer includes a top layer patterned structure; a top piezoelectric layer comprising a first piezoelectric material, wherein the top piezoelectric layer is adjacent to the top layer; a middle layer including one or more middle layer metal electrodes, wherein the middle layer is adjacent to the top piezoelectric layer opposite the top layer; a bottom piezoelectric layer comprising a second piezoelectric material, wherein the bottom piezoelectric layer is adjacent to the middle layer opposite the top piezoelectric layer; and a bottom layer including one or more bottom layer metal electrodes, wherein the bottom layer is adjacent to the bottom piezoelectric layer opposite the middle layer, and wherein in a second area, the bottom layer includes a bottom layer patterned structure, wherein the top layer metal electrodes include a first plurality of electrodes inter-digitated with a second plurality of electrodes, wherein a first one of the inter-digitated metal electrodes in the top layer and a first one of the metal electrodes in the bottom layer are coupled to a first contact configured to provide a first signal, and a second one of the inter-digitated metal electrodes in the top layer and a second one of the metal electrodes in the bottom layer are coupled to a second contact configured to provide a second signal; the layers suspended over a cavity by tethers; the top layer patterned structure or the bottom layer patterned structure controlling a resonant frequency response of the piezoelectric resonator device.