An Interferometric Modulator (IMod) is a microelectromechanical device for modulating light using interference. The colors of these devices may be determined in a spatial fashion, and their inherent color shift may be compensated for using several optical compensation mechanisms. Brightness, addressing, and driving of IMods may be accomplished in a variety of ways with appropriate packaging, and peripheral electronics which can be attached and/or fabricated using one of many techniques. The devices may be used in both embedded and directly perceived applications, the latter providing multiple viewing modes as well as a multitude of product concepts ranging in size from microscopic to architectural in scope.

Interferometric modulation of radiation

This paper reviews the recent progress in MEMS for radio frequency (RF) applications from a device perspective. RF MEMS devices reviewed include switches and relays, tunable capacitors, integrated inductors, mechanical resonators and filters, and some representative microwave and millimetre-wave components. Important device parameters are highlighted, as they have significant contributions to the performance of the final products in which the devices are used. The challenges and statuses of these RF MEMS devices are outlined and discussed. The intent of this topical review is to provide perspective to newcomers in the field, and empower potential end-users with an overall device picture, current status, and a vision of their ultimate performance capabilities.

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RF MEMS from a device perspective

An overview of recent progress in the research and development of micromachined devices for use in wireless communication subsystems is presented. Among the specific devices described are tunable micromachined capacitors, integrated high-Q inductors, micromachined low-loss microwave and millimeter-wave filters, low-loss micromechanical switches, microscale vibrating mechanical resonators with Q's in the tens of thousands, and miniature antennas for millimeter-wave applications. Specific applications are reviewed for each of these components with emphasis on methods for miniaturization and performance enhancement of existing and further wireless transceivers.

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Micromachined devices for wireless communications

The invention provides a microfabrication process which may be used to manufacture a MEMS device. The process comprises depositing one or a stack of layers on a base layer, said one layer or an uppermost layer in said stack of layers being a sacrificial layer; patterning said one or a stack of layers to provide at least one aperture therethrough through which said base layer is exposed; depositing a photosensitive layer over said one or a stack of layers; and passing light through said at least one aperture to expose said photosensitive layer.

A method for fabricating a structure for a microelectromechanical systems (mems) device

In this paper, a closed-form expression for the pull-in voltage of fixed–fixed beams and fixed–free beams is derived starting from the known expression of a simple lumped spring-mass system. The effects of partial electrode configuration, of axial stress, non-linear stiffening, charge re-distribution and fringing fields are all included in the final expression. Further, the results obtained are summarized and validated with other existing empirical and analytical models as well as with finite element simulation results. The model agrees well with finite element simulation results obtained with COVENTORWARE software.

https://iopscience.iop.org/article/10.1088/0960-1317/12/4/319/pdf

Pull-in voltage analysis of electrostatically actuated beam structures with fixed–fixed and fixed–free end conditions

() ABSTRACT: An RF MEMs microelectromechanical system variable capacitor has been demonstrated with a 22:1 tuning range, tuning from 1.5 to 33.2 pF of capacitance. This capacitor was constructed using bistable MEMs membrane capacitors with individual tuning ranges of 70:1 to 100:1, control voltages in the 30-55 V range, switching speeds less than 10 mS, and operating frequencies as high as 40 GHz. These devices may eventually provide a viable alternative to electronic varactors with improved tuning range and lower loss. Q 1999 John Wiley & Sons, Inc. Int J RF and Microwave CAE 9: 362)374, 1999.

RF MEMs variable capacitors for tunable filters

A switch includes a conductive region, a membrane, and a dielectric region. The dielectric region is formed from a dielectric material and is disposed between the membrane and the conductive region. When a sufficient voltage is applied between the conductive region and the membrane, a capacitive coupling between the membrane and the conductive region is effected. The dielectric material has a resistivity sufficiently low to inhibit charge accumulation in the dielectric region during operation of the switch.

Zhimin J. Yao

Papers

RF MEMs variable capacitors for tunable filters

Method and apparatus for switching high frequency signals