Review on Radio Frequency Micro Electro Mechanical Systems (RF-MEMS) Switch

Miniaturization of mechanical or electromechanical systems has paved the way to develop Micro Electro Mechanical Systems (MEMS), and they have the potentials for application in communication systems. Radio Frequency MEMS (RF-MEMS) switches can be used as an alternative to mechanical and semiconductor devices-based switches such as PIN diodes or varactor diodes for their better isolation, reduced insertion loss, low-power consumption and higher-power handling capabilities. There are various constraints involved in designing RF-MEMS switch like finite or limited time to toggle, prone to failure, power handling capacity, RF performance, material selection, etc. Hence, it is necessary to properly select key parameters and optimize the switch to achieve desired outcome for specific applications. This paper discusses design constraints and various parameters involved in designing RF-MEMS switch. From the review, it is found that shunt-type configuration of RF-MEMS switch with electrostatic actuation, capacitive contact type and bridge structure are suitable for millimetre wave applications which are explored for future bandwidth hungry communication systems.