A high power-handling RF MEMS tunable capacitor using quadruple series capacitor structure

This paper presents an RF MEMS tunable capacitor that achieves excellent power-handling property with relatively low actuation voltage. The tunable capacitor consists of two fixed MIM (Metal-Insulator-Metal) capacitors and two MEMS capacitor elements, all connected in series. This quadruple series capacitor (QSC) structure enables to reduce the actuation voltage without sacrificing the power-handling capability, since the MIM capacitor reduces the RF voltage amplitude applied to the MEMS capacitors. Measured result demonstrates +36dBm hot-switching at 85C with 21V pull-in voltage.