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 is presented in this work. The multimode technique is based on simultaneous excitation of 4 TE modes in a flat waveguide, whose width a is much larger than its height b. The flattened waveguide is filled homogeneously with the material sample to be characterized. The multiple coaxial to waveguide coupling structure has been designed to allow for the orthogonal separation of the multiple eigenmodes in the waveguide. For each of the 4 propagating 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. First measurements demonstrate the validity of the multimode waveguide adapter and proves the properties of the manufactured coupling structure.