RF MEMS Switches and Integrated Switching Circuits

Abstract

Abstract-Radio frequency (RF) microelectromechanical systems (MEMS) have been pursued for more than a decade as a solution of high-performance on-chip fixed, tunable and reconfigurable circuits. This paper reviews our research work on RF MEMS switches and switching circuits in the past five years. The research work first concentrates on the development of lateral DC-contact switches and capacitive shunt switches. Low insertion loss, high isolation and wide frequency band have been achieved for the two types of switches; then the switches have been integrated with transmission lines to achieve different switching circuits, such as single-pole-multi-throw (SPMT) switching circuits, tunable band-pass filter, tunable band-stop filter and reconfigurable filter circuits. Substrate transfer process and surface planarization process are used to fabricate the above mentioned devices and circuits. The advantages of these two fabrication processes provide great flexibility in developing different types of RF MEMS switches and circuits. The ultimate target is to produce more powerful and sophisticated wireless appliances operating in handsets, base stations, and satellites with low power consumption and cost.

A Dual Cylindrical Tunable Laser Based on MEMS

“…By using of this technology free space components can be realized. The important applications of this technology are optical crossconnect switches [16][17][18][19] and micro-optical free-space benches. The main advantage for this technique that the components after fabrication become self-assembled.…”

“…In our model, a plane wave expansion method is used [8,19]. In this method the effect of transfer function of free space between laser facet and external reflector, called diffraction effect, is taken into account.…”

ANN model of RF MEMS Lateral SPDT switches for millimeter wave applications

“…The FGCPW is formed by thick single-crystal-silicon plate that has been coated with thin layer of aluminum (Al) to make the RF signal propagation not only along the metal on the top surface, but also on the sidewalls of the transmission line. In this switch, two cantilever beams are employed and can be used as signal lines together to propagate RF signal [14]. The fixed connections of the two cantilever beams are from the same port and the two contact tips are on the other port.…”

“…with the assumption that the two cantilever beams are identical [14]. Hence, only the circuit model of the single beam switch is discussed in this paper.…”

Vertical, capacitive microelectromechanical switches produced via direct writing of copper wires

“…MEMS switches operated by radio frequencies are essential components in the circuit architectures of a variety of MEMS-based systems 3 . As an electromechanical switch, MEMS switches offer markedly lower power consumptions, better isolations, and lower insertion losses compared with conventional field-effect transistors or PIN-diodebased switches 3,4 . MEMS switches are typically fabricated with silicon-surface micromachining technology and are typically planar, which requires a large surface budget on integrated circuit chips 5 .…”