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Mode matching technique-based modeling of coaxial and circular waveguide discontinuities for material characterization purposes

Published online by Cambridge University Press:  28 September 2011

Emmanuel Decrossas*
Affiliation:
Department of Electrical Engineering, University of Arkansas, Fayetteville, AR 72701, USA. Phone: + 1 479 575 6851.
Mahmoud A. EL Sabbagh
Affiliation:
Department of Electrical Engineering and Computer Science, University of Syracuse, Syracuse, NY 13244, USA.
Victor Fouad Hanna
Affiliation:
Université Pierre et Marie Curie (Paris 6), Paris, France.
Samir M. El-Ghazaly
Affiliation:
Department of Electrical Engineering, University of Arkansas, Fayetteville, AR 72701, USA. Phone: + 1 479 575 6851.
*
Corresponding author: E. Decrossas Email: edecrossas@ieee.org

Abstract

In this paper, it is proposed to use a cylindrical cell for the characterization of dielectric material. The extraction of complex permittivity is based on inverse gradient approach where the full-wave simulation results are mapped to experimental data to extract the complex permittivity. As the operational frequency of radio frequency (RF)/microwave devices is increased, it becomes difficult to accurately model waveguide transitions using traditional methods based on meshing such as finite-element method (FEM) where mesh size is determined according to the wavelength. Moreover, these techniques usually require extensive computational resources. Mode matching technique (MMT) is the full-wave tool implemented in this current work. It is used to compute the generalized scattering matrices (GSMs) of the different discontinuities of test setup. These GSMs model precisely discontinuities as they include the effects of all higher-order modes propagating and evanescent. Simulation and experimental results are included to validate the proposed approach for the rigorous modeling of those discontinuities and hence the extraction of complex permittivity.

Type
Research Papers
Copyright
Copyright © Cambridge University Press [2011]. This is a work of the U.S. Government and is not subject to copyright protection in the United States

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References

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