A switched high-T_c superconductor microstrip resonator using a MEM switch

We have used a high performance (less than 0.05 dB insertion loss, greater than 30 dB isolation) high-T_c superconductor based micro electromechanical (MEM) switch to insert a shunt microstrip resonator into a microstrip transmission line thus forming a 'T'-resonator structure. This allows the insertion of a series of notches and peaks (depending on termination of the shunt line and the harmonic in use) into the transmission line's transfer function thus forming a rudimentary switched filter. The 'T'-resonator is designed for a resonant frequency of 3.5 GHz and is implemented using high-T_c YBa₂Cu₃O₇, BaTiO₃ is used as a dielectric patch underneath a suspended gold membrane. The design, fabrication, testing and most recent results are presented in this paper.