Applied Theory of Electromagnetic Scattering and Diffraction

This text is based on the lecture notes written for the post-graduate course in radio engineering, given at the Radio Laboratory of the Helsinki University of Technology in the spring semester of 2005. Solid knowledge of scattering and diffraction phenomena is the key for understanding a very large variety of radio and microwave applications. It is of course obvious that diffraction defines radar visibility of airplanes, ships, and other objects, but also radiation of antennas, for instance, can be considered as the process of scattering into space by the metal body of the antenna. The side-lobe and back-lobe levels of large reflector antennas are determined by diffraction on the reflector edge. Similar observations can be made, for instance, about matching waveguide devices. The matching effect is due to reflection and diffraction by some inhomogeneities inserted in a waveguide. The course is an advanced level introduction into the theory of scattering an diffraction of electromagnetic waves. Although the existing literature on scattering and diffraction is very large, we could not find a text book that would be appropriate for the course. For this reason, we have compiled lecture notes, and in this volume some part of the lecture material is systemized and presented in the book form