Rigorous Multi-modal Analysis of Partially Filled Waveguides for Accurate Permittivity and Permeability Retrievals

Determination of the permittivity and permeability for penetrable materials is very important in many applications. Partially filled waveguide (PFW) method enjoys the feature of reduced fabrication precision requirement for the material sample under test. In the original paper proposing the PFW method, a small-edge-partially-filled waveguide (PFW-s) was analyzed by considering only the longitudinal section magnetic modes, which is obviously wrong. This mistake had been pointed out and corrected in our recent conference papers. In the present paper, the formulas previously derived for the PFW-s configuration is extended straightforwardly to the asymmetric big-edge-partially-filled waveguide (PFW-b) configuration, which enjoys the feature of easy positioning of the material sample compared with the common center-loaded PFW-b configuration. Also, the formulation of the asymmetric PFW-b configuration is simpler than that of PFW-s configuration. Numerical tests show that the derived formulas can successfully retrieve both permittivity and permeability distributed on the full complex plane.