Scattering of electromagnetic waves from arbitrary cross section shaped coating located on a perfectly conducting cylinder

The aim of this thesis is to analyze a group of methods for solving the problems of scattering of electromagnetic waves from dielectric coating located on a perfectly conducting cylinder. Although there is a huge number of methods for coatings with simple geometries in literature, limited number of works exist for coatings with variable thickness. In this work, first, the direct scattering problem is introduced and reduced to a boundary value problem. While the scattering problems related to circular coatings can be solved analytically in terms of series involving Bessel and Hankel functions, this is not possible for arbitrary variying coatings. In such a case, one can apply one of the mostly used methods which is based on Method of Moments. For the method based on Method of Moments, the boundary value problem is reduced first to the solution of a Fredholm integral equation of second kind through the Green?s function of the medium involving conducting cylinder. In the second stage of the thesis a new method based on the analytical continuation of the scattering field is proposed. In this method, first, a ring which covers the outher surface of the coating is determined. The inner boundary of the ring is chosen as the maximum circle covering the coating surface from inside while the outher boundary is the minimum circle covering the coating surface from outside. Then, the scattered field is expanded into Taylor series inside the ring while it is represented through the series involving Bessel and Hankel functions in the regions outside the ring The methods are tested and compared by considering several simulative examples. According to numerical results obtained from the applications, it is observed that the proposed method is working properly except the coatings having a large dielectric coefficient. Furthermore, since the number of unknowns in the analytical continuation method is much less than those of the Method of Moments, the new method produces results much faster than Method of Moments. Keywords: Electromagnetic Waves, Wave Scattering, Direct Scattering Problems, Method of Moment.