Superconducting Tunable Microstrip Gap Resonators Using Low Stress RF MEMS Fabrication Process

A Nb superconducting tunable microstrip gap resonator has been designed and fabricated with low stress Au RF MEMS dc-contact switches. The resonator can be tuned in four states from 12-15 GHz. Simulations show that the resonator Q is highly sensitive to the contact resistance of the MEMS when the switches are actuated. Measurements confirm that the Q degrades from 200 to 50. RF performance of the resonator is investigated at cryogenic (4 K) temperatures while the Nb is superconducting.