Low temperature superconductive tunable bandstop resonators and filters

A superconducting MEMS varactor is reported. The device is fabricated using a standard Niobium superconductor foundry process. Utilizing this varactor a superconducting tunable notch resonator is implemented. The tunable resonator has a measured tunability of more than 20% from 3.22 GHz to 2.54 GHz with a biasing voltage from 0 V to 78 V. A 3-pole bandstop filter is also fabricated and tested. Simulation results of the tunable bandstop filter demonstrates a 20% shift in center frequency.