Modeling and Validation of Capacitive Type RF MEMS Switches for Low Actuation Voltage and High Isolation

Design objectives in capacitive type radio frequency micro electro mechanical switches (RF-MEMS) are to reduce actuation voltages and to obtain low insertion losses with high isolation. In this study, we report design, modeling and simulation of three new structural configurations using ANSYS to obtain the optimum geometry; further high frequency simulations are performed using HFSS to obtain low insertion losses and high isolation. The designed switches require only 3.9 to 5 V as pull-in voltage for actuation. The mechanical resonant frequency and quality factor are in the range of 6.5 to 8.7 kHz and 1.1 to 1.2, respectively. Switching times for all the designs are 32 to 38 μs at their respective pull-in voltages. Two of the switch designs have insertion loss of less than 0.25 to 0.8 dB at 60 and 50 GHz, and isolation greater than 58 dB for all three designs.