RF MEMS miniature-switched capacitors with pull-down and pull-up electrodes for high power applications

This paper presents miniature RF MEMS switched capacitors with pull-down and pull-up electrodes for increased capacitance ratio and power handling. A 2×2 switch array has three operation states: up-state, down-state and up-up state (switch attached to the pull-up electrode), with capacitances of 115 fF, 370 fF and 64 fF, respectively. The pull-up electrode increases the capacitance ratio from 3.2 (standard operation with no pull-up electrode) to 5.8. The pull-up electrode also solves the problem of RF self actuation and the 2×2 switch was tested up to 4 W at 5 GHz (pull-up electrode engaged) with no change in the measured S-parameters.