Higher-order modes in dielectric resonators for measurement of loss tangent

The paper focuses on the utilisation of higher-order shielded dielectric resonator modes to measure the loss tangent of a dielectric resonator and its variation with frequency. Using a full-wave, rigorous mode-matching technique, resonant frequencies and energy storage/power loss inside the cavity are determined for several resonant modes. Resonant modes with high electric and magnetic energy filling factors are identified and subsequently used in the measurement. By measuring the loss tangent at the resonant frequency of each chosen higher-order resonant mode, the frequency variation of the loss tangent can be established. Therefore the task of measuring the frequency variation of the loss tangent of dielectric resonators can be achieved with the use of a single specimen and metallic cavity