Scattering By Metallic Semi-Circular And Quarter-Circular Cylinders Located Inside Corner Reflectors

The analysis of the electromagnetic fields and specially the analysis of the currents on metallic scatterers and at the different intersections of the scatterer surfaces are important and have a wide range of applications. This research presents the analytical solution of the electromagnetic scattering problem by two different scattering structures. The first scatterer structure is a metallic semi-circular cylinder which is protruding from one of the faces of a metallic dihedral corner reflector that occupies the surfaces (x > 0, y > 0, z = 0) and (x > 0, z > 0, y = 0) of a rectangular coordinate system, and is intersected perpendicularly by the other face of the reflector. The second scatterer structure consists of a metallic quarter-cylinder, its axis coincident with the positive z-axis, located inside a metallic trihedral reflector consisting of three quarter planes occupying the surfaces (x > 0, y > 0, z = 0), (y > 0, z > 0, x = 0) and (x > 0, z > 0, y = 0) of a rectangular coordinate system (x, y, z). The incident primary wave is a plane wave with arbitrary polarization and is obliquely incident on the metallic structure of the scatterers, which are immersed in free space. The scattered field is determined exactly, in the phasor domain. The solution of the three-dimensional problem is based on the solution of the two-dimensional problem where the incident wave falls normally on the cylindrical structure in the absence of the truncating plane z = 0. The solution to this two dimensional problem is found explicitly in terms of the electric and magnetic fields everywhere by combining the scattering by an infinitely long cylinder with the method of images. Then the two-dimensional solution is utilized to obtain the more general three-dimensional solution for the case of an obliquely incident plane wave. In the last step of the solution, the introduction of the truncating plane z = 0 is dealt with by using the method of images. All the derivations and analysis are done separately for each of the two metallic structures and for each case both E-polarization and H-polarization of the incident wave are considered. In particular, exact formulas for the surface electric current density on the structure are determined and discussed. The behavior of the fields for electrically large and small radii with different incident angles are examined and discussed in detail. The continuity of the current at the intersection of different portions of the scatterer structure is verified. Chapter 1 is a review of known material, while chapters 2 and 3 contain the novel results obtained in this thesis.