Clapp-type oscillators for high temperature pressure sensor systems
AssigneeThe United States of America as represented by the Administrator of the National Aeronautics and Space Administration
InventorMaximilian C. Scardelletti
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Abstract
Pressure sensors are disclosed that may perform health monitoring in-situ in harsh operating environments. The pressure sensors may be based on a Clapp-type oscillator that includes one or more resistors, one or more inductors, capacitors, a sensor, and a transistor. Such pressure sensors may be particularly well-suited various applications, such as gas turbine engines, oil and gas extraction, vehicle engines, and exhaust monitoring.
Claims20
An apparatus, comprising:
- an inductor;
- a pressure sensing capacitor connected to the inductor in series;
- a first capacitor;
- a second capacitor;
- and
- a field effect transistor (FET) connected to the inductor, the pressure sensing capacitor, the first capacitor, and the second capacitor, wherein
- the inductor, the pressure sensing capacitor, the first capacitor, the second capacitor, and the FET form a common source Clapp-type oscillator, and
- the apparatus is configured to operate at temperatures in excess of 400° C.
A capacitive pressure sensor, comprising:
- an inductor;
- a pressure sensing capacitor connected to the inductor in series;
- a first capacitor;
- a second capacitor;
- a field effect transistor (FET) connected to the inductor, the pressure sensing capacitor, the first capacitor, and the second capacitor;
- a gate;
- a drain;
- and
- DC bias circuitry operably connected to the gate and the drain, the DC bias circuitry comprising a series resistor on the gate, two metal-insulating-metal (MIM) capacitors in shunt, and a wirewound inductor on the drain, wherein
- the inductor, the pressure sensing capacitor, the first capacitor, the second capacitor, and the FET form a common source Clapp-type oscillator, and
- the capacitive pressure sensor is configured to operate at temperatures in excess of 400° C.
A common source Clapp-type oscillator, comprising:
- an inductor;
- a pressure sensing capacitor connected to the inductor in series;
- a first capacitor;
- a second capacitor;
- and
- a field effect transistor (FET) connected to the inductor, the pressure sensing capacitor, the first capacitor, and the second capacitor.
Dependencies are inferred from the claim text.