Date of Award


Document Type


Degree Name

Master of Science in Electrical Engineering


Department of Electrical and Computer Engineering

First Advisor

Michael J. Havrilla, PhD


This research presents a method by which electromagnetic characterization of materials in a partially filled waveguide can be accurately performed. Higher order modes are excited by the geometry, which are not accounted for in most algorithms. A correction must consider the power transmitted by higher-order modes. Modal solutions, using reference plane independence, for a single top air gap between the material sample and the waveguide wall, are also presented. Characterization is performed on samples of acrylic and rubberized magnetic radar absorbing material. Calculation of the complex permittivity and permeability of shielding material, within 10% of the true value, was achieved by using less than 15 modes. Improvement of real permittivity is the strongest feature of the algorithm. The inclusion of the reference plane independence analysis greatly improves the level of performance. Results are presented in S-band and X-band.

AFIT Designator


DTIC Accession Number