Patent ID: 8686614

Claim:
A device comprising: a suspended mechanical resonating structure having a first surface and a second surface opposite the first surface; a substrate coupled to the suspended mechanical resonating structure such that ends of the suspended mechanical resonating structure are free; four electrical ports; and four electrodes formed on the first surface, each one of the four electrodes being coupled to a respective one of the four electrical ports, wherein the four electrical ports include two input ports configured as a differential input port and two output ports configured as a differential output port, and wherein the mechanical resonating structure is formed of multiple layers, the layers comprising: a first temperature compensating layer; a second temperature compensating layer; a conductive layer forming a conductive plane, wherein the conductive layer contacts the second temperature compensating layer; and an active layer comprising a piezoelectric material, wherein the active layer contacts the conductive layer, wherein the first and second temperature compensating layers compensate for temperature induced changes in a resonance frequency of the mechanical resonating structure, wherein at least one of the first and second temperature compensating layers comprises Silicon Dioxide, and wherein the piezoelectric material is Aluminum Nitride or Silicon.