T.B.A. Senior received his PhD from Cambridge University in 1954 and is now a Professor and Associate Chairman in the Department of Electrical Engineering and Computer Science at the University of Michigan. He is the author of two other books, numerous book chapters and over 200 journal articles on electromagnetic scattering. He is a Fellow of the IEEE, a Vice-President of the International Union of Radio Science and was the recipient of the 1993 van der Pol Gold Medal.J.L. Volakis is a Professor in the Department of Electrical Engineering and Computer Science at the University of Michigan. He obtained his PhD from Ohio State University in 1982 and spent two years at Rockwell International working on the BIB aircraft programme before going to Michigan. He has published over 100 articles on computational and analytical methods in electromagnetics and was an Associate Editor of the IEEE Trans, on Antennas and Propagation. Currently he serves as an Associate Editor of Radio Science and edits the EM Programmer's notebook published in the IEEE Antennas and Propagation Magazine.

• Chapter 1: IntroductionChapter 2: First order conditionsChapter 3: Application to planar structuresChapter 4: Application to impedancewedgesChapter 5: Second order conditionsChapter 6: Higher order conditionsChapter 7: GIBC applications to cylindricalbodiesChapter 8: Absorbing boundary conditionsAppendix A: Generalised Rytov analysisAppendix B: Special functionsAppendix C: Steepest descent methodAppendix D: PO diffraction coefficient forimpedance wedges