Fundamental Study Of MRTD In Electromagnetic Scattering

In order to accurately solve electromagnetic problems in engineering, with the aidof modern computer technologies and techniques, various computational methods aredeveloped in predicting characteristics of electromagnetic fields. The finite differencetime domain (FDTD) technique, introduced by K. S. Yee in 1966, is one of the mostwidely using methods. It remains a key goal to increase the computational efficiency ofthe method in a manner that retains its many desirable features by reducing node density.In 1996, Krumpholz and Katechi first introduced the multireslution time domainscheme, which can significantly save computer resource for both CPU time andmemory capacity by reducing the grid density for the analysis of fundamentalelectromagnetic problems.This research work aims at developing a systematic multiresolution time domainschemes based on previous FDTD views of both theories and practical applications. Infirst several chapters, we discuss the fundamental theories including generalized FDTDformulations, the way to adding incident, perfectly matched layers absorbing boundaryconditions, transformation from near zone fields to far zone fields, and then wecalculate time domain scattering characteristic of objects as well as frequency domain,and bi-station scattering property of randomly rough surface, further more the transientfar-field response of three-dimensional objects have been obtained. Generalized MRTDformulations, on the basis of Haar wavelet function, has been developed in last severalchapters, and an anisotropic perfectly matched layer (APML) for the truncation an openspace as well as GPML. For the beginner, we calculate the reflection coefficient for asingle-layer dielectric system; next we investigate a two-slab dielectric system in whichtwo slabs are separated by a distance of 9cm. Also we investigate the RCS characteristicof two-dimensional conduct objects using Haar-MRTD method. What is more, thetechniques of 3D Haar-MRTD are presented. The results have been validated throughcomparisons with MOM.