HTS split open-ring resonators with improved power-handling capability for reaction-type transmitting filters

Novel planar construction of high-temperature superconducting (HTS) filters that improve power-handling capability is proposed. Split open-ring resonators are developed to be used in reaction-type transmitting filters that have very sharp bandstop characteristics. Resonator structures to achieve high-unloaded Q-factors and low radiation as well as low surface current densities in the passband are numerically investigated for 5 GHz band operation. Low surface current densities reduce the generation of intermodulation distortions. Measurements confirm an unloaded Q-factor of 68 000 and third intermodulation- distortion of -82 dBc at 30 dBm input power.