Simultaneous Determination of Complex Permittivity and Permeability of Columnar Materials With Arbitrarily Shaped Cross Section

Abstract

An effective simultaneous evaluation method for the complex permittivity and permeability of lossy materials is proposed by applying it to an arbitrarily shaped cross-sectional post placed in a rectangular waveguide. We use one sample and only measure S(21) parameters for two different locations of the sample. The measurement of complex reflection parameter S(11) is not required in this evaluation method. The scheme of electromagnetic field analysis for the evaluation is based on the extended spectral-domain approach combined with the mode-matching method, which is accurate and efficient, and can be flexibly used for the iterative fitting operation for the estimation of material parameters. Sample preparation and setting is significantly easier in this method compared to conventional methods. The error caused by deviations in the setting of a sample is investigated. The estimated values for the sample material by this procedure show good agreement with the results obtained using the conventional method over the X-band.