An improved measurement technique for retrieval of effective constitutive properties of thin dielectric/magnetic and metamaterial samples

An improved partially filled waveguide based technique for the simultaneous measurement of complex permittivity and permeability of thin dielectric-magnetic and metamaterial samples is presented. The proposed approach requires placing a test specimen longitudinally at the centre of a rectangular waveguide cross section for the measurement of scattering coefficient in the specified frequency band. The constitutive properties of the specimen are determined in terms of the measured scattering coefficients using the newly derived expressions, which are based on the solution of the corresponding transcendental equation. The proposed approach is validated by measuring the permittivity and permeability of few standard samples, and comparing the results with the data available in literature. The overall procedure is non-iterative, which makes it quite versatile, and envisages the possibility of even online monitoring of certain parameters.