Design and investigation of microwave bandpass filters for L- and R-frequency bands based on high-temperature superconducting films

The microstrip hairpin half-wave 9-pole bandpass YBCO filter for L- and R-band, bandwidth about 3%, has been designed and manufactured from double-sided YBCO film on 2" sapphire wafer with CeO/sub 2/ buffer sublayer. The designed housing gives minimum contribution of a normal metal to the surface resistance of HTS films. The microwave power loss in the designed filter in a copper housing at 1.7 GHz was 0.7 dB at 77 K.