Patent ID: 7181975

Claim:
A pressure sensor, comprising: a pressure sensing capacitor comprising: a housing defining a cavity, a diaphragm, supported on said housing and separating said cavity from an external pressure region, said diaphragm comprising a conductive material, an electrode disposed on said housing inside said cavity and facing said diaphragm so as to define a gap between at least part of said diaphragm and at least part of said electrode, wherein said electrode is arranged such that said diaphragm can roll against said electrode in capacitive contact therewith so as to vary the contact area upon displacement of said diaphragm; an insulating layer disposed between said electrode and said diaphragm to provide a dielectric layer between said electrode and said diaphragm, and an inductor, formed on said housing, electrically connected to said pressure sensing capacitor so as to form an LC tank circuit, wherein said gap varies as a function of a pressure differential applied to said diaphragm such that the capacitance of said pressure sensing capacitor varies, and whereby, an electromagnetic signal can be applied to the pressure sensor to detect the resonant frequency of said LC tank to determine said pressure differential.