Measurement of complex permittivity and permeability and thickness of multilayered medium by an open-ended waveguide method

A circular waveguide radiating into a layered medium is used for the determination of permittivity and permeability of materials. Better accuracies are obtained by modeling an air gap between the hanged waveguide and material. Simultaneous determination of complex permittivity and thickness of the material is also possible. Theoretical results have been compared with those obtained by the Finite Element Method. Many measurement have been made on a few materials with various dielectric and magnetic losses and the results have been comparable to those obtained using the well known free space method of Gaussian focused beams.