Chapter: Investigations of the wave propagation in waveguides with inhomogeneous dielectric inclusions are performed using advanced analytical and numerical methods. A particular attention is paid to the analysis of benchmark problems: forward and inverse scattering by parallel-plane dielectric diaphragms and layered structures placed in a rectangular waveguide with perfectly conducting walls. A detailed study of the properties of transmitted fields using the theory of functions of one or several complex variables leads to the development of a technique aimed at reconstructing permittivity of the inclusions from the transmission coefficient. The unique solvability of this inverse problems is proved by establishing the domains where the transmission coefficient is a one-to-one function of permittivity and other problem parameters. The obtained results are used to improve FDTD numerical solution to the corresponding forward and inverse scattering problems for Maxwell’s equations in waveguides and create specifically developed codes. In general, the chapter contributes to the electromagnetic wave theory with several new findings and modified theoretical approaches.
Book: This book covers recent achievements in the area of advanced analytical and associated numerical methods as applied to various problems arising in all branches of electromagnetics. The unifying theme is the application of advanced or novel mathematical techniques to produce analytical solutions or effective analytical-numerical methods for computational electromagnetics addressing more general problems. Each chapter contains an outline of its topic, discusses its scientific context and importance, describes approaches to date, gives an exposition of the author's approach to the problem tackled in the chapter, describes the results, and concludes with a discussion of the range or class of problems where the techniques described work most appropriately and effectively. Intended primarily for researchers in the fields of electrical engineering, mathematics, physics and related disciplines, the book offers systematic and thorough coverage of this complex topic. It is hoped that the book will help to stimulate further investigation and discussion of the important problems in electromagnetics within this research community.