讲座题目：Prof.Kobayashi: Radar Cross Section of a Thin Material Strip （薄材料带线的雷达散射截面分析）
主 持 人：颜志老师
Dr. Kobayashi is a professor of the Department of Electrical, Electronic, and Communication Engineering, Chuo University, Tokyo, Japan. Prof. Kobayashi is a Member of Science Council of Japan and a Fellow of The Electromagnetics Academy. His research area includes, developments of rigorous mathematical techniques as applied to electromagnetic wave problems, integral equations, boundary value problems, special functions, radar cross section, and scattering and diffraction. Prof. Kobayashi received several distinguished awards including, M. A. Khizhnyak Award (2016) for contribution to electromagnetic theory and V. G. Sologub Prize (1998) for contribution to development of analytical regularization methods.
The analysis of the scattering by material strips is an important subject in electromagnetic theory and radar cross section (RCS) studies. In this lecture, we shall reconsider Volakis’s problem and analyze the plane wave diffraction by a thin material strip with the aid of the Wiener-Hopf technique. Both E and H polarizations are considered. Introducing the Fourier transform of the scattered field and applying approximate boundary conditions in the transform domain, the problem is formulated in terms of the simultaneous Wiener-Hopf equations, which are solved exactly via the factorization and decomposition procedure. However, the solution is formal since branch-cut integrals with unknown integrands are involved. By using a rigorous asymptotic method we have developed recently, we shall derive a high-frequency solution of the Wiener-Hopf equations, which is expressed in terms of an infinite asymptotic series and accounts for all the higher order multiple diffraction effects rigorously. It is shown that our solution is valid for the strip width greater than about the incident wavelength and requires numerical inversion of an appropriate matrix equation. The scattered field in the real space is evaluated asymptotically by taking the Fourier inverse of the solution in the transform domain and applying the saddle point method. It is to be noted that our final solution is uniformly valid in incidence and observation angles. Numerical examples of the RCS are presented for various physical parameters and far field scattering characteristics of the strip are discussed in detail. Some comparisons with the existing literature are also given.