| Study on the objects wideband electromagnetic scattering has important theoretical and practical significance for target identification. In this thesis, three methods of the target band electromagnetic scattering are studied: method of moments (MoM), MoM combined with the inverse Fourier transform (MoM+IDFT) and time domain integral equation method (TDIE) method. The main works are:1. The RWG basis function is chosen as testing functions to derive matrix equation and the matrix element computation method of the efficient kurnerical evaluation of the face-pair combinations. MoM is applied to the calculation of radar cross section (RCS). Bistatic RCS of metallic ball through MoM agrees with that of Mie theory, which proves the correctness of MoM.2. The generation of the face-pair combinations and the extraction of calculated data in MoM is analysed. At the same time, the accurate integral expressions on triangulated surfaces are given in detail. Finally, three kinds of RCS(bistatic station, single station and broadband) of the four flat cylinder targets with different shapes is calculated and analyzed.3. The basic methods of broadband electromagnetic scattering are compared and analyzed, which include time domain method, frequency domain method and time-frequency extrapolation method. Using the mathematical form of the Gaussian pulse is to derive the discrete Fourier transform(DFT) and the inverse discrete Fourier transform(IDFT) formula. The basic steps of using MoM combining with IDFT to compute frequency band electromagnetic scattering are introduced. Finally, we calculate the target surface current response on time.4. The time domain electric field integral equation on the conductor surface is introduced; The solutions of the explicit time stepping equation and the far scattered field are given; The reasons for the divergence of the marching-on-in-time (MOT) algorithm are discussed; The average MOT method is proposed. The numerical examples show the effectiveness of this method. |
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