Wideband CMOS Compatible Capacitive MEMS Switch for RF Applications

This letter presents the design, fabrication, and characterization of a novel capacitive radio frequency (RF) microelectromechanical system (MEMS) switch. The switch uses thermal actuation and a finger structure for capacitive coupling. The switch is CMOS process-compatible and uses a two step maskless reactive ion etching (RIE) micromachining technique for post-processing. The measurement results show that the insertion loss is 1.6 dB and isolation is 33 dB at 5.4 GHz. The applications of this switch are ISM/WLAN CMOS front-end reconfigurable RF circuits such as voltage controlled oscillators, filters, and matching networks.