title: A High Isolation Series-Shunt RF MEMS Switch.
abstract: This paper presents a wide band compact high isolation microelectromechanical systems (MEMS) switch implemented on a coplanar waveguide (CPW) with three ohmic switch cells, which is based on the series-shunt switch design. The ohmic switch shows a low intrinsic loss of 0.1 dB and an isolation of 24.8 dB at 6 GHz. The measured average pull-in voltage is 28 V and switching time is 47 μs. In order to shorten design period of the high isolation switch, a structure-based small-signal model for the 3-port ohmic MEMS switch is developed and parameters are extracted from the measured results. Then a high isolation switch has been developed where each 3-port ohmic MEMS switch is closely located. The agreement of the measured and modeled radio frequency (RF) performance demonstrates the validity of the electrical equivalent model. Measurements of the series-shunt switch indicate an outstanding isolation of more than 40 dB and a low insertion loss of 0.35 dB from DC to 12 GHz with total chip size of 1 mm × 1.2 mm.
authors.affiliation: Department of Physics, Nanjing University, Nanjing, 210093, China; E-Mail:  yshi@nju.edu.cn.
authors.forename: Yuan-Wei
authors.initials: YW
authors.lastname: Yu
authors.forename: Jian
authors.initials: J
authors.lastname: Zhu
authors.forename: Shi-Xing
authors.initials: SX
authors.lastname: Jia
authors.forename: Yi
authors.initials: Y
authors.lastname: Shi