Accuracy issues in surface resistance measurements of high temperature superconductors using dielectric resonators

Reproducible and accurate measurements of the surface resistance of high temperature superconductors are essential for the development and commercialization of the next generation of high performance cryoelectronic systems. Dielectric resonators are the best, most accurate technique for this measurement and have been suggested for the international standard technique. This paper discusses trade-offs amongst the various types of dielectric resonators including choices of the dielectric rod, the metallic enclosure, the electrical measurements of Q-factor, resonant frequency and coupling coefficients, and other issues to ensure reproducible and accurate measurements.