Survey on Various Types of Rf Mems and Its Classification

Advancements and Limitations of RF MEMS Technology for Microwave Applications

Abstract

RF MEMS technology for microwave applications is in the area of surfacemicromachined actuators for the realization of microwave switches. Thesepossess very high linearity, low dc standby power and low insertion loss. Theseswitches are based on electrostatic attraction counterbalanced by suitablemechanical forces on the beam to pull the switch into the right position. Thisswitch can be designed to present nearly 50 impedance across a broad range offrequencies when closed and nearly an open circuit when there is no connection.This property makes this an attractive choice for microwave applications.Several new switch architectures have also been reported, including theair-bridge structure. This structure utilizes very high capacitance variationto achieve the switching action. This scheme, however, suffers from relativelyhigh switching voltage requirements.