Micro electromechanical structures (MEMS) technology have facilitated innovative approaches in the design and development of effective and low cost microwave circuits and systems. This technology is expected to have significant application in the development of reconfigurable systems and architectures. This paper presents an overview/review of the evolution of MEMS based subsystems and devices, specifically switches, transmission lines, filters, phase shifters and antennas. Thispaper also discusses the key issues in the analysis and the design of MEMS based devices, popularly called RF MEMS with primary emphasis on MEMS switches.
Indexing terms: MEMS, RF, Micro machining.comprised oflow-energy, low-cost, adaptive and highperformance RF devices. A number of enabling technologies including novel circuit architectures, adaptive and reconfigurable phased array antennas, advanced materials and novel integration and packaging methods are required for these type of RF systems. Such systems need to be developed for microwave up to sub-millimeter-wave frequencies, since the next generation of the communication networks will be specifically designed in these bands, due to their significant advantages in bandwidth and miniaturization [2].The existing technology enables the design and fabrication of all the basic transceiver components (amplifiers, oscillators, mixers, doublers, filters, antennas, switches and so on) on planar substrates. Most of these components that are commercially .available~re built on the mature well-known semico l1 ductor technology based on diodes' and transistors. Although this technology dominates both analog and digital circuits, a research effort on micro machining and Micro-Electro-Mechanical Systems (MEMS) is expected to enhance or even replace the existing systems [3]. MEMS have been identified as the most significant enabling technologies in developing miniaturized, low-cost and low-energy RF components and systems. This paper provides a review of the MEMS based subsystems and devices and also discusses the issues in respect ofdesign and analysis of RF MEMS devices. 175Paper No 156-F; Copyright (6) 2008 by the JETE.Although significant effort has been made on the development of neoteric modulation tec1friiques and network protocols (spread spectrum channels, CDMA and DSL protocols, new voice over IP protocols, etc) the RF front-end technology has received significantly less attention up to now [I]. Since the RF front-end is the basic interface between a typical microwave communication system and its environment, the challenges of reconfigurability, spectrum efficiency, security, miniaturization and cost minimization can only' be met by ensuring that the RF front-end is W ITH ever-increasing demand for efficient communications at low-cost, the need for multifunctional, adaptive and low-power systems is on the rise. Furthermore, modern communication systems have to suppress the harmful effects ofthe interference from other users who share the same channel and the self-interference due to multip...