Design and fabrication of compact superconducting filters and antennas using high quality YBCO films

摘要

We investigated the relationship between Rs and Jc of YBCO thin films, and examined that How to reduce the surface resistance of YBCO thin films on MgO and sapphire substrates, especially on r-cut and c-cut plane of sapphire substrates' and found that in-plane orientation of the grains was most important parameter to reduce the surface resistance. We could obtain the perfect in-plane oriented YBCO thin films on MgO and r-cut plane sapphire substrates, however, it was difficult on c-cut plane sapphire substrates. Because, c-cut plane of the sapphire substrate is hexagonal synmetry. Also we designed the compact superconducting filters of cross-coupled hair pin filter by an electromagnetic simulator. We found that the skirt properties of the filter are superior to that of Chevyshev type filter. Superconducting patch array antennas were also fabricated by YBCO thin films and measured the gain, directivity and stability of these array antennas using compact cooling system.