A method of evaluating the temperature dependences of dielectric resonators and materials

The intrinsic temperature coefficient of the resonant frequency TCf0, which is defined as the temperature coefficient of a resonant frequency when all the stored energy is confined inside a dielectric rod, is introduced to evaluate the temperature dependences of dielectric materials. The temperature coefficient of the resonant frequency TCf for a dielectric rod resonator can be estimated accurately from the TCf0 value. Actually, for shielded dielectric resonators of three types; parallel plate, image, and MIC types, it is shown that the TCf values can be estimated with the error of ±0.7 ppm/°C from the measured TCf0 value having the experimental error of ±0.5 ppm/°C