Microwave measurements of surface impedance of high-T/sub c/ superconductors using two modes in a dielectric rod resonator

A novel technique using two resonant modes in a dielectric rod resonator, the TE/sub 021/ and TE/sub 012/ modes, is proposed to measure the surface impedance Z/sub s/=R/sub s/+jX/sub s/, where R/sub s/ is the surface resistance and X/sub s/ is the surface reactance of high-T/sub c/ superconductors at microwave frequency. The temperature dependence of Z/sub 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/sub s/ measurement is comparable to the conventional two-resonator method using two ceramic rod resonators, The excellent repeatability in the X/sub s/ measurement is superior to that of the two-resonator method.