DIELECTRIC RESONATORS AS MICROWAVE CHARACTERIZATION TOOLS

Dielectric resonators, formed by sandwiching a cylindrical piece of po lished dielectric material (sapphire) between two planar endplates, of fer an attractive platform for microwave testing of HTS films, Each re sonator is tested as a two-port system, by exciting and detecting the modal fields with loop-terminated coaxial cables, The observed quality factor of the resonator is a gauge of the surface resistance of the e ndplates, We discuss utilization of this method as a tool for testing similar to 1 cm(2) areas, at frequencies in the 20-40 GHz range, and a t cryogenic temperatures, using field analysis to explore trade-offs i nvolving cylinder geometry, field confinement, and miniaturization. An improved method for analyzing two-port data eases the difficulties as sociated with testing the resonator in a cryogenic environment.