Design and parameter-extraction based small-signal modeling of a novel center-anchor MEMS series switch

A novel center-anchor MEMS series switch is presented in this paper. A signal-line gap of 270 um, which is two or more times broader than that of a conventional MEMS switch, is achieved, constituting a substantial improvement of the isolation characteristic. This is attributed to the formation of a broad gap by the center-anchor, which sufficiently limits off-state coupling. The measured isolation is -58 dB to -34 dB at 5-35 GHz, whereas that of insertion loss is -0.28 dB to -0.34 dB. Also, a parameter-extraction based small-signal pi model is newly developed for evaluation of the center-anchor MEMS switch. Accurate agreement between the measured and modeled RF performances demonstrates the validity of the proposed model.