A hybrid mode-matching spectral domain approach for evaluation of complex permittivity of lossy materials in cylindrical cavity

The cylindrical cavity resonator method is presented to evaluate the complex relative permittivity of lossy materials. The loaded sample in the cavity is required to have the rotational symmetry but may have bulky and/or wide sample. To measure the sample at the specified frequency with high Q, movable dielectric supports with low permittivity and low loss are loaded in cavity. Theoretical basis of the method is the hybrid electromagnetic field analysis, i.e. the extended spectral domain approach combined with mode-matching method (ESDMM). The proposed evaluation method is verified with virtual experiments as well as actual measurements.