Design and Simulation of RF MEMS Switch using Uniform Serpentine Flexure Four Meander Type Beam

Abstract

In this paper four meander Serpentine flexures based movable beam structure has been used for design and development of capacitive contact RF MEMS switch for high frequency and space application. The developed MEMS switch is design on silicon wafer having the high resistivity ($\rho \gt 8 k\omega-cm$), high dielectric constant ($\varepsilon_{\mathbf{r}}= 11.8$) and low loss tangent ($tan\delta=0.001$,). Meander techniques are used to achieve the low pull-in voltage. The simulated value of pull-in voltage for four meander beam is 2.5 V for initial air height of 2.5 $\mu {\mathrm {m}}$. The developed switch exhibits the simulated RF parameters i.e. Insertion loss in Upstate (S21), return loss (S11), and Isolation (S21) are greater than 0.2, 20, and 30 dB respectively, across the complete frequency range (DC-40 GHz). The Method of Moments based ADS (advanced design system) and Finite element Method based coventorware and ANSYS HFSS full-wave simulator has been used for electromagnetic and electromechanical analysis of the 3D structure. The simulated Figure of merit (ratio of down state capacitance to up state capacitance) of the proposed switch is greater than 85. Further, The Simulated RF data are validated with equivalent circuit modal data over the entire frequency range.