Electrical characteristics of thin-film Ba2YCu3 O7 superconducting ring resonators

The development of high-temperature superconducting thin films has opened up new opportunities for microstrip applications to exploit the low-loss properties of these films. It is reported that the microwave performance of superconducting microstrip ring resonators between 2 and 22 GHz for which both microstrip and ground plane were fabricated from Ba2YCu,0, films deposited on both sides of the same LaAIO, substrate. At 9.5 GHz, resonances were observed with intrinsic Q's of - 7500 at 75 K and - 20,000 at 25 K. The 75 K value represents an improvement of a factor 20 over Au.