Method for Measuring the Complex Permittivity Using the Ridged Waveguide

The new technique for measuring the complex permittivity of materials in a wide microwave frequency range has been developed. The double ridged waveguide has been used as a measuring cell. The proposed technique allows to increase the accuracy of measurements by placing the dielectric sample between the ridges of the waveguide, in the place of maximum concentration of electromagnetic energy of the fundamental wave. For the double ridged waveguide with dielectric filling, electrodynamic characteristics have been calculated, such as propagation constants and cutoff frequencies. The structure of the fundamental HE-wave at the operating frequency has been determined and visualized. The measurement results of the complex permittivity of the ebonite sample have been presented.