Improvement of Pull-in Voltage for RF MEMS Switch Based on NiTi Actuator

This paper presents the design and RF characterization of low voltage series Micro-Electro Mechanical (MEMS) switch using Shape Memory Alloy (SMA). Nitinol (NiTi) was used as SMA material in this work for its thermo mechanical properties of super elasticity and shape memory effect. The simulation result shows that the use of a SMA beam to actuate switching allows the excitation voltage to be relatively much lower compared to that needed for electrostatic actuation. The displacement versus voltage characteristics was obtained using Intellisuite software. The RF performance of the switch was carried out using Ansoft High Frequency Structural Simulator (HFSS) and electrostatic analysis was done using Intellisuite. The RF Performance of the switch results in an insertion loss of -0.0002dB and an isolation of -25.78dB. The pull down voltage has been reduced into 6V and switching speed is 10.71µs.