Power-Handling Capability of Superconducting Filters Using Disk- and Ring-Type Bulk Resonators

The critical current of a bulk resonator is larger than that of a thin film resonator. Therefore, we investigated a transmitting filter that uses high temperature bulk superconducting resonators to increase their power-handling capability. We designed disk- and ring-type 3-pole bulk superconducting resonator filters using MW-studio software and calculated the current density distribution. From the simulation, the power-handling capability of the disk-type bulk filter was found to be approximately 1.3 times that of the ring-type bulk filter. These filters were fabricated and tested. The frequency response and the power-handling capability were measured at 20 K. The filters showed band-pass properties. The power-handling capability of the disk-type bulk filter was 41.7 W and that of the ring-type bulk filter was 26.6 W. Therefore, the disk-type filter had an approximately 1.6 times higher power-handling capability than did the ring-type filter.