Investigation On Fast Methods For Analyzing Electromagnetic Scattering Characteristics Of Multiple Random Objects

Electromagnetic scattering problem is an important research area inelectromagnetics. It is very important and practical to investigate fast andefficient numerical methods for analyzing electromagnetic scatteringcharacteristics of multiple random objects.Sparse matrix canonical grid method, characteristic basis functionmethod and asymptotic waveform evaluation technique are investigatedintensively. These numerical methods are used to analyze electromagneticscattering characteristics or wide-band electromagnetic scatteringcharacteristics of random objects in this thesis.The basic principle of the method of moments and sparse matrixcanonical grid (SMCG) method are introduced firstly. Electromagneticscattering characteristics from three-dimensional random dielectric objects areanalyzed by using SMCG method. Based on SMCG, two preconditioned sparsematrix canonical grid methods are presented and numerical results show thatthe presented method is correct and efficient. Then the theory of characteristicbasis function method is introduced and used to analyze electromagneticscattering characteristics from two-dimensional multiple random dielectricobjects. Finally, the asymptotic waveform evaluation technique is introducedand applied to the method of moments to calculate the wide-band radar crosssection from two-dimensional perfect electric conductor and dielectric randomobjects.In brief, the investigation is very useful not only in further studying theelectromagnetic scattering characteristics and wide-band electromagneticscattering characteristics of complex random objects, but also in developingthe wide-band radar, ultra wide-band radar and new stealth materials.