Fabrication of high temperature superconducting microstrip resonator with high Q and low power dependence

A microstrip resonator at Ku band was designed and fabricated using a high-temperature superconducting thin film. The YBa/sub 2/Cu/sub 3/O/sub 7-x/ thin film used in this research was deposited on SrTiO/sub 3/ substrate using rf magnetron sputtering. The film exhibits unique microwave properties: high temperature operation (89 K) and low surface resistance (better than 1/20 that of copper at Ku band). The microstrip resonator with a resonant frequency of 12 GHz at 90 K was 60 times better than an analogous copper counterpart and had a low power dependence up to 90 K. Various characteristics of the resonator are presented. The fabrication technique using a high temperature superconducting thin film improves the performance of the filter.