Dielectric waveguide resonator with a superconductive boundary layer

This paper reports on dielectric waveguide resonators shown to exhibit high Q's limited by the dielectric loss. High resonator Q is desirable in measuring the microwave attenuation of superconducting materials. The properties of a dielectric waveguide resonator with a superconductive boundary layer have been investigated. The microwave properties of YBaCuO and NbN thin films have been investigated by employing them as boundary layers on the dielectric waveguide. Transmission and reflection measurements on the dielectric waveguide resonance were performed from 20-40 GHz using a vector network analyzer. The temperature dependence of the loaded Q of the resonator was measured under weak coupling. The results were found to be in agreement with the predictions of the Drude model for T ≥ Tc and the Mattis-Burdeen theory for T ≤ Tc