Determination of the permittivity and permeability for some low-loss and high-loss microwave materials

This paper contributes to the validation and experimental determination of the complex permittivity and permeability of microwave materials intended for use with antennas. The two-port microwave scattering coefficients were measured for samples of the materials in closed coaxial and rectangular waveguide systems. A non-iterative and stable version of the Nicholson Ross and Weir transmission reflection technique was used to determine the complex constitutive parameters. Extracted results for microwave materials including Aluminium Nitride, Boron Nitride and a Silicone binding agent are presented. Some preliminary data on a manufactured Barium Titanate and Carbon fibre polymer composite microwave absorber is also described.