A novel multimodal waveguide technique for the broadband characterization of dielectric material parameters

The concept of a novel multimodal waveguide measurement technique for the broadband determination of dielectric material properties will be presented in this work. The multimode technique is based on simultaneous excitation of 4 TE modes in a waveguide section whose cross section is designed in a way that the waveguide width a is much larger than its height b. The flattened waveguide is filled homogeneously with the material sample to be determined. The multiple coaxial to waveguide coupling structure has been arranged to allow the orthogonal separation of the multiple eigenmodes in the waveguide. For each of the 4 TE eigenmodes a separate TRL calibration procedure in waveguide regime is performed. A multi-port Vector Network Analyzer has been used to measure the S-Parameters at the coaxial ports. A first measurement demonstrate the validity of the multimode waveguide adapter and proves the properties of the manufactured coupling structure with the assumptions made in the analysis.