Low temperature superconducting DC-contact RF MEMS switch for superconducting tunable resonators

A novel niobium-based superconducting DC-contact RF MEMS switch is presented for the first time. The switch is amenable to integration with the superconducting micro-electronics (SME) technology. A comparison of the switch RF performance at room and cryogenic temperatures indicates a great improvement in the insertion loss of the switch when niobium is superconducting. The mechanical characteristic of the switch at extremely low temperature (4K) is investigated. The switch exhibits only 18% increase in the actuation voltage as temperature changes from room temperature (300K) to 4K. A niobium superconducting tunable resonator is designed and fabricated employing the proposed switch as the tuning element. The concept can be extended to realize a high-Q switched capacitor bank for reconfigurable RF front-end components in SME receivers.