Simplified method for measurements and calculations of coupling coefficients and Q^o factor of high-temperature superconducting dielectric resonators temperature superconducting dielectric resonators

Abstract

To accurately determine the surface resistance of high temperature superconducting films, multi-frequency measurements of S^21, S^11 and S^22 and sophisticated data processing are required. As a result, surface resistance measurements and calculations for varying temperatures are very time consuming. In this paper we introduce a simplified method for calculations of the unloaded Q (Q^0) factor, which require measurements of s^11 and s^22 at the lowest temperature only. For all other temperatures s^21 measurements are needed only. The method has shown to give sufficiently accurate Q^0 values, and hence the surface resistance of superconducting samples, as compared to results obtained from S^21, S^11 and S^22 measurements using the transmission mode q-factor technique. The presented method has been tested under different coupling coefficients and frequencies.