Variable capacitance membrane actuator for wide band tuning of microstrip resonators and filters
AssigneeHRL Laboratories, LLC
InventorsJonathan J. Lynch, Sarabjit Mehta, John Pasiecznik, Peter Petre
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Abstract
A device for varying the capacitance of an electronic circuit is disclosed. The device comprises a flexible membrane located above the electronic circuit, a metal layer connected to the flexible membrane, and bias circuitry located above the membrane. Variation of the capacitance of the electronic circuit is obtained by pulling the membrane upwards by means of the bias circuitry. The disclosed device provides a sizeable capacitance variation and high Q factor, resulting in overall low filter insertion loss. A nearly constant group delay over a wide operating bandwidth is also obtained.
Claims18
A device for tuning an electronic circuit, comprising:
- a moveable membrane, wherein changes in distance between the membrane and the electronic circuit produce changes in capacitance of the electronic circuit;
- and
- a first capacitive arrangement operatively associated with the membrane, comprising a first capacitor plate and a second capacitor plate, wherein the first capacitor plate is located at a first distance from the electronic circuit and connected with the membrane, and the second capacitor plate is located at a second distance from the electronic circuit, the second distance being greater than the first distance.
A membrane actuator for tuning an electronic circuit, comprising:
- a first substrate;
- a first conductive material disposed on the first substrate and containing the electronic circuit, the first substrate and the first conductive material forming a first layer;
- a flexible membrane;
- a second conductive material contacting the flexible membrane, the flexible membrane and the second conductive material forming a second layer, the flexible membrane and second conductive material being disposed above the first substrate and first pattern;
- a second substrate;
- a third conductive material contacting the second substrate, the second substrate and third conductive material forming a third layer, wherein:
- a parallel plate capacitor having an upper plate and a lower plate is formed between the second layer and the third layer, the second conductive material forming the upper plate of the capacitor and the third conductive material forming the lower plate of the capacitor, and
- when a bias voltage is applied between the upper plate and the lower plate, an electrostatic force is produced, causing the membrane to deform, thereby varying the capacitance of the electronic circuit.
Dependencies are inferred from the claim text.