Capacitive pressure sensor having encapsulated resonating components
US6789429B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 8, 2003 |
| Grant date | Sep 14, 2004 |
| Priority date | — |
| Expiry date | Apr 8, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L9/0072
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A capacitive pressure sensor for measuring a pressure applied to an elastic member includes a capacitive plate disposed adjacent to the elastic member so as to define a gap between a planar conductive surface of the elastic member and a corresponding planar surface of the capacitive plate. The gap, capacitive plate and elastic member together define a capacitor having a characteristic capacitance. The sensor further includes an elongated electrical conductor characterized by an associated inductance value. The conductor is fixedly attached to and electrically coupled with the capacitive plate. The gap between the capacitive plate and the elastic member varies as a predetermined function of the pressure applied to the elastic member so as to vary the characteristic capacitance. The capacitor and the electrical conductor together form an electrical resonator having a characteristic resonant frequency. Varying the capacitance of this tank circuit varies the resonant frequency of the tank circuit. Thus, the resonant frequency of the tank circuit is indicative of the pressure applied to the elastic member. The close physical proximity of the capacitor and the electrical conductor equali…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.