Patent ID: 8755541

Claim:
A microelectromechanical microphone comprising: a diaphragm moveably coupled with an anchor, the anchor being fixedly coupled to a substrate; a backplate, separated from the diaphragm by a dielectric fluid, the backplate being fixedly coupled to the anchor by a dielectric solid, there being a first capacitance between the backplate and the diaphragm and a second capacitance between the backplate and the anchor; a sensor attached to the anchor, for measuring a capacitance between the backplate and the diaphragm, the measured capacitance being substantially equal to the sum of the first capacitance and the second capacitance; a reference electrode spaced from the backplate within a layered structure, the anchor and reference electrode being formed from the same material and being in the same layer within the layered structure wherein the reference electrode is embedded within the dielectric solid, there being a third capacitance between the reference electrode and the backplate that is substantially the same as the second capacitance; and a circuit that subtracts the third capacitance from the capacitance measured by the sensor to produce an output capacitance that is substantially the same as the first capacitance.