Regularized 1-D Dielectric Profile Inversion in a Uniform Metallic Waveguide by Measurement and Simulation

• Published in: IEEE transactions on microwave theory and techniques Vol. 60; no. 5; pp. 1437 - 1443
• Main Authors: Kilic, E., Siart, U., Eibert, T. F.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01-05-2012; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied classical electromagnetism; Applied sciences; Circuit properties; Complex permittivity; Dielectric measurements; Dielectrics; Diffraction, scattering, reflection; Electric, optical and optoelectronic circuits; electromagnetic scattering inverse problems; Electromagnetic wave propagation, radiowave propagation; Electromagnetic waveguides; Electromagnetism; electron and ion optics; Electronics; Equations; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Image reconstruction; Inverse; Inverse problems; iterative methods; Mathematical models; Microwave circuits, microwave integrated circuits, microwave transmission lines, submillimeter wave circuits; Microwaves; Nonhomogeneous media; optimization methods; Permittivity; Physics; Radiocommunications; Radiowave propagation; Reconstruction; Regularization; Telecommunications; Telecommunications and information theory; Waveguides; Performance evaluation; iterative methods; K band; Iterative method; Dielectric measurement; Optimization; Numerical data; s parameter; Dielectric measurements; Integral equation; Complex permittivity; Electromagnetic wave scattering; electromagnetic scattering inverse problems; Dielectric materials; X band; Multiple layer; Lossy medium; Centimetric wave; optimization methods; Dielectric metal interface; Algorithm; Waveguide; Electromagnetic wave; Inverse problem; Simulation; Wave scattering; A priori estimation
• ISSN: 0018-9480; 1557-9670
• DOI: 10.1109/TMTT.2012.2187922

An iterative technique for the reconstruction of longitudinally inhomogeneous lossy dielectric material loaded in a uniform metallic waveguide is addressed in this paper. The problem is first formulated as an inverse scattering one based on an integral equation in terms of the unknown complex permittivity. By using knowledge of scattering parameters, the Gauss-Newton technique is employed to solve the inverse problem with both the Tikhonov regularization and multiplicative regularization. In order to show the effectiveness of the method, it is tested against numerical and experimental data at X - and K -bands and satisfactory reconstructions are obtained. Experimental results show that the inverse algorithm with multiplicative regularization can be used for the characterization of multilayered structures in a waveguide without needing a priori information.