Circuit Modelling and Eigenfrequency Analysis of a Poly-Si Based RF MEMS Switch Designed and Modelled for IEEE 802.11ad Protocol

Abstract

This paper presents the equivalent circuit modelling and eigenfrequency analysis of a wideband robust capacitive radio frequency (RF) microelectromechanical system (MEMS) switch that was designed using Poly-Si and Au layer membrane for highly reliable switching operation. The circuit characterization includes the extraction of resistance, inductance, on and off state capacitance, and Q-factor. The first six eigenfrequencies are analyzed using a finite element modeler, and the equivalent modes are demonstrated. The switch is optimized for millimeter wave frequencies, which indicate excellent RF performance with isolation of more than 55 dB and a low insertion loss of 0.1 dB in the V-band. The designed switch actuates at 13.2 V. The R, L, C and Q-factor are simulated using Y-matrix data over a frequency sweep of 20-100 GHz. The proposed switch has various applications in satellite communication networks and can also be used for devices that will incorporate the upcoming IEEE Wi-Fi 802.11ad protocol.

Modeling Method of Finite Element Modeler and Electromagnetic Solvers for Education and Research in RF MEMS

“…In RF industry, performance and size of the devices are limiting factor especially for RF MEMS [16], [17]. For RF MEMS Switches, scattering parameters are analysed to check its RF performance.…”

“…For this proposed switch, the spring constant, stress and pull-in voltage required for actuation is analyzed as discussed in [5], [20]. COMSOL Multiphysics is used as finite element modeler for analyzing the parameters [17], [20]. This section deals with the coupled physics, electrostatic + magnetic problem solving.…”