MEMS variable capacitor with stabilized electrostatic drive and method therefor
AssigneeMotorola, Inc.
InventorsJi-Hai Xu, Jenn-Hwa Huang, John Michael Parsey, Jr.
Life of this patent
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Abstract
A micro electro-mechanical systems device having variable capacitance is controllable over the full dynamic range and not subject to the “snap effect” common in the prior art. The device features an electrostatic driver (120) having a driver capacitor of fixed capacitance (121) in series with a second driver capacitor of variable capacitance (126). A MEMS variable capacitor (130) is controlled by applying an actuation voltage potential to the electrostatic driver (120). The electrostatic driver (120) and MEMS variable capacitor (130) are integrated in a single, monolithic device.
Claims18
A Micro Electro-Mechanical system (MEMS) device, comprising:
- an electrostatic MEMS driver, comprising:
- a first driver capacitor having a fixed capacitance;
- and
- a second driver capacitor having a variable capacitance, wherein the first driver capacitor is in series with the second driver capacitor;
- and
- a MEMS variable capacitor, wherein the MEMS variable capacitor is controlled by the electrostatic MEMS driver.
A Micro Electro-Mechanical system (MEMS) device, comprising:
- a driver capacitor pair, comprising:
- a first driver capacitor having a fixed capacitance;
- and
- a second driver capacitor having a variable capacitance, wherein the first driver capacitor is in series with the second driver capacitor;
- and
- a MEMS variable capacitor, wherein the MEMS variable capacitor is controlled by the driver capacitor pair.
A micro electro-mechanical system device, comprising:
- a substrate;
- an isolation layer fabricated over the substrate;
- a MEMS variable capacitor, comprising:
- a lower plate coupled to the substrate;
- a dielectric membrane;
- and
- an upper plate coupled to the dielectric membrane;
- a first driver capacitor having a fixed capacitance comprising:
- a lower electrode coupled to the substrate;
- and
- a dual-use electrode wherein the dual-use electrode is separated from the lower electrode by the isolation layer;
- and
- a second driver capacitor having a variable capacitance, in series with the first driver capacitor, the second driver capacitor comprising:
- the dual-use plate;
- and
- an upper electrode coupled to the dielectric membrane;
- wherein the MEMS variable capacitor, the first driver capacitor and the second driver capacitor are fabricated on a monolithic, integrated device.
Dependencies are inferred from the claim text.