Rotary RF MEMS Switch Based on the Wobble Motor Principle

A novel, truly rotary, single-pole eight-throw (SP8T) RF MEMS switch is reported. The concept is an adaptation of the axial-gap electrostatic wobble motor. Details of the switch design and fabrication process are presented, together with initial test results for prototype devices. DC contact resistance measurements have been made over half a million rotations, yielding an average contact resistance of 2.5 Ω. The switch shows promising RF performance, with insertion loss varying smoothly from 0.6 dB at 2 GHz to 4 dB at 20 GHz, and isolation better than 31 dB across the frequency range 0.5 to 20 GHz.