Micro electro-mechanical variable capacitor

Abstract

The invention relates to a micro electromechanical variable capacitor, wherein, movable comb electrodes with opposite polarities which are simultaneously manufactured on a same substrate are independently actuated. The polarities are formed into cross comb form to maximize the capacitance of a device. The change of the lateral wall overlapping area between cross comb fingers provides the expected capacitance regulation of the device. The stiffness of the electrodes is lowered through using thin supporting structures on the end parts of the electrodes. The three-dimensional features of the device are beneficial to realize larger surface area. Larger capacitance change and regulation range are obtained through independently actuating the electrode fingers. A plurality of working modes of the device result in wider flexibility and larger performance advantage of the device. During the manufacturing of the device, single substrates with etched dielectrics are used for packaging the device. Thus, no additional packaging is required. In addition, the alignment and the conjugation can be finished in the wafer scale. Therefore, the improved device yield can be obtained with low cost.

Description

technical field [0001] The present invention relates generally to micro-electromechanical system (MEMS) devices, and more particularly to variable capacitors utilizing three-dimensional comb drive electrodes that can be integrated into prior art semiconductor fabrication processes. Background technique [0002] In high frequency and radio frequency (RF) circuits, variable capacitors or variable reactors are basic elements. In recent years, MEMS variable capacitors have attracted considerable attention due to their excellent electrical characteristics. [0003] Although variable capacitors using MEMS technology can be easily implemented in standard semiconductor devices used in aerospace, consumer electronics, and communication systems, researchers have been working hard to improve the maximum capacitance adjustment range achieved by parallel plates. Adjustable range of MEMS variable capacitors. This is attributed to the nonlinear electrostatic force during the actuation. ...

AI Technical Summary

Problems solved by technology

In addition, the device is a three-port varactor and does not provide multiple actuation modes to enhance the adjustable range of the device

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