A micro-electro-mechanical system (MEMS) switch is described. The MEMS switch includes both RF-input and output transmission lines formed on a substrate. An RF armature is anchored to the substrate and is electrically connected with the RF-output transmission line. A contact is electrically connected with the RF-input transmission line. Both bias-input and output signal lines are formed on the substrate. A bias armature is anchored to the substrate and is electrically connected with the bias-input signal line. A DC/RF isolation insulator connects the bias armature with the RF armature. When a charge is introduced to the bias-input signal line, the bias armature is forced toward the bias-output signal line, thereby forcing the RF armature to connect with the contact and form an electrical circuit between the RF-input transmission line and the RF-output transmission line.

A micro-electro-mechanical switch is described. The switch comprises a substrate, with a signal transmission portion and an activation portion attached with the substrate. The activation portion includes an armature activation electrode positioned above a substrate activation electrode. The signal transmission portion includes a metal contact extending from a conducting transmission line and through a bottom insulating layer of the signal transmission portion, thereby being exposed for electrical contact. A mechanical linkage connects the activation portion with the signal transmission portion so that the activation portion and the signal transmission portion move in concert. When an activation signal is applied along the activation portion, both the activation portion and the signal transmission portion are drawn toward the substrate to a substantially closed position, where the metal contact of the signal transmission portion electrically contacts a signal transmission electrode.

Micro-electrical-mechanical systems are fabricated in a substrate having a sacrificial layer sandwiched between two semiconductor layers. The semiconductor layers are selectively etched to create non-etched frames and etched microstructures immobilized within the frames by the sacrificial layer. An adhesive sheet is attached to one surface of the substrate, and the substrate is diced into chips, each including one frame and one immobilized microstructure. The sacrificial layer is then selectively etched to free a movable member in each microstructure. Finally, the chips are detached from the adhesive sheet, each chip becoming a micro-electrical-mechanical system. This fabrication method provides a simple and inexpensive way to avoid damage to the microstructure during the dicing process.

A method is provided of continuously varying the capacitance of a MEMS varactor having a cantilever assembly mounted on a base portion, the cantilever assembly having a first capacitance plate and a dielectric element mounted thereon, and the base portion having a second capacitance plate mounted thereon. The method includes applying a first actuation voltage to deform the cantilever assembly until the dielectric element contacts the second capacitance plate leaving a gap therebetween, and applying a second actuation voltage larger than the first actuation voltage to further deform the cantilever assembly to reduce the gap between the dielectric element and the second capacitance plate.

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.