Conclusion
Dielectric resonators - Microwave circuits

The dielectric resonator confines 95% of the electromagnetic energy in the TE resonance mode_01δ. Characterizing this mode—like a resonant cavity—in terms of resonance frequency and quality factor is a method for determining the dielectric tangent of the material. Low values, below 10^–4, can be measured—typically for dielectric permittivities greater than 20—in a practical and cost-effective manner. The article [E 1 922] details the characterization of the material’s other properties: permittivity, thermal stability, and the dielectric loss tangent for permittivities below 20.