Development of a Millimeter-Wave Coaxial Cable Measurement System at Cryogenic Temperature and Measurement of the Surface Resistance of High-T_c Superconductor Films(<特集>Special Issue on Superconductive Electronics)

A coaxial cable measurement system applicable up to 60 GHz in the cryogenic temperature is developed by using V-connectors. In this system, the fine location of coupling loop antennas can be adjusted by three-dimensional mechanical stages in the low temperature region. In order to verify usefulness of this system, the temperature dependence of surface resistance (R_s) of Y-Ba-Cu-O (YBCO) films was measured at 30 GHz by the two-dielectric resonator method using TE_<011-> and TE_<013-> mode sapphire rod resonators. The measured result of R_s was 0.5 mΩ at 30 GHz and 20 K, which was 1/40, compared with those of copper plates.copyright(c)2002 IEICE許諾番号：07RB017