Electromagnetic scattering from Conical Horn analysis using wavelet-based moment method

Abstract

In this paper Conical horn Antenna has been analyzed by two methods, the first one is an asymptotic one which is the aperture integration based on the geometrical optics (GO), the second one is a numerical method based on the well known moment method and improved by wavelets. In this work we intend first to introduce the application of wavelet in electromagnetic scattering, then a comparison of the two method of analysis is presented to show the limit of use of the asymptotic method and to emphasize on the fact that moment method is an exact method which is improved by the introduction of wavelet by reduction of both memory space and processing time, this is well presented and compared with different type wavelets.Index Terms-Moment Method, Wavelets, Horn antenna, Aperture integration.which is an asymptotic method, with the wavelet technique which is based on the moment method for future combination between these two methods, because for very large size structures, even very powerful methods may face the problem of memory space and computing time. Many work have been curried out using wavelet to solve electromagnetic problems the results are very promising [8][9][10] [11]. The conical horn antenna is excited at the mode TEll and the frequency of work is 12 GHz.The theoretical contents is expressed in the next section, which consists of three subsections, The first subsection is dedicated to the Aperture integration and problem description, the second subsection is about integral equation and Moment Method formulation, the last subsection is for orthogonal wavelet expansion and finally Numerical results. II. FORMULATION A. Moment Method Formulation A.l Integral equationThe current density is expressed by the tangential components, the fact that the antenna is a body of revolution, the current is expanded as follow:K(J(r» =~J(r)-nX 1J(r')XV'G(r, r').ds' (1) K(J(r)) = Ii X Hi (r)(2) +00 J(t, rp) = I [J t (t, rp).t + J 9' (t, rp).~lejv.9'The Conical Horn is studied in 2D as shown in figure 1, the surface of this latter is considered to be perfect conductor. Using the boundary condition, the scattered field may be written as an integral magnetic equation in two dimensions as [12].