Temperature characterization of dielectric-resonator materials

Dielectric resonators are widely used as components of microwave resonant cavities with extremely high Q factors. To design a temperature-compensated resonator it is necessary to know accurately the value of τε, the temperature coefficient of the dielectric constant. A simple and accurate procedure is described to measure this quantity. Furthermore, the paper discusses uncertainties involved in the use of another quantity, τf, which is nowadays supplied by the manufacturers of dielectric resonators to characterize the temperature variation of dielectric resonators.