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Chang, Albert Hoon 2014-12-15T19:05:33Z 2014-12-15T19:05:33Z 10000-01-01 1988 1988 In the past two decades, the conventional method of moments (MoM) utilizing the subdomain basis functions has been widely used to solve a variety of electromagnetic scattering problems. However, the size of the scatterers that can be analyzed by using MoM is limited to only a few wavelengths due to the storage requirements in the computer. In this report, two approaches that allow one to circumvent the storage problem inherent in the conventional MoM are investigated and applied to various types of large thin scatterers. One alternative to directly inverting the large MoM matrix is to recast the problem into a form that is suitable for solution via iterative schemes. Although the use of iterative methods may enable one to treat scatterers that are an order of magnitude larger electrically, most of them are not well-suited for handling multiple excitations in an efficient manner. Some variational-iteration schemes based on the use of prechosen basis functions that are suitable not only for treating larger bodies but for handling multiple incident angles as well are suggested. Another way to reduce the storage requirement is through the use of techniques by which one can temper the growth in the size of the impedance matrix to a reasonable level even as the scatterer becomes large in terms of the wavelength. In this report, this goal is achieved by developing a hybrid method in which high-frequency techniques or exact solutions to certain canonical problems are utilized to choose an appropriate set of entire or semi-entire basis functions that incorporate the actual physics of the scattering phenomenon. Made available in DSpace on 2014-12-15T19:05:33Z (GMT). No. of bitstreams: 1 8823095.pdf: 4605514 bytes, checksum: 933441b0a972b91965ccb1a98c0272af (MD5) Previous issue date: 1988 Embargo set by: Seth Robbins for item 69559 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs U of I Only 187 p. Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1988. http://hdl.handle.net/2142/69393 (UMI)AAI8823095 Engineering, Electronics and Electrical Numerical Methods for Solving the Problem of Electromagnetic Scattering From Large Bodies text Electrical Engineering Electrical Engineering University of Illinois at Urbana-Champaign Dissertation Ph.D.