Microwave measurements of surface impedance of high-Tc superconductors using two modes in a dielectric rod resonator

A novel technique using two resonant modes in a dielectric rod resonator, the TE₀₂₁ and TE₀₁₂ modes, is proposed to measure the surface impedance Z_s=R_s+jX_s , where R_s is the surface resistance and X_s is the surface reactance of high-T_c superconductors at microwave frequency. The temperature dependence of Z_s can be obtained from only one time measurement as a function of temperature, although the conventional two-resonator method needs to repeat the measurement for temperature twice. The high precision in the R_s measurement is comparable to the conventional two-resonator method using two ceramic rod resonators, The excellent repeatability in the X_s measurement is superior to that of the two-resonator method