An Image-Type Dielectric Resonator Method to Measure Surface Resistance of a High-T_c Superconductor Film(Special Issue on Superconductor Digital/Analog Circuit Technologies)

copyright(c)2003 IEICE 許諾番号：07RB0174A new measurement method using two resonance modes, the TE_021 and TE_012 modes, in an image-type dielectric resonator is proposed to measure the surface resistance R_s of only one high-T_c superconductor (HTS) film and the loss tangent tan δ of a sapphire rod separately, precisely and nondestructively. The image-type resonator is constructed by placing a sapphire rod in a bottom of a conductor cavity made of two HTS films and a copper ring. This resonator is designed from the mode charts calculated on the basis of the rigorous analysis by the mode matching method, taking account of an uniaxial-anisotropic characteristic of sapphire. It is verified that the mode charts are also effective to identify many resonance modes observed in measurement. The temperature dependence of R_s of one YBCO film was measured at 19.3 GHz by this method. The measured result agreed very well with one measured by the conventional two-dielectric resonator method. As a result, it was verified that this method is useful to evaluate R_s value of one HTS film with no damage