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|Title:||Numerical Methods for Solving the Problem of Electromagnetic Scattering From Large Bodies|
|Author(s):||Chang, Albert Hoon|
|Department / Program:||Electrical Engineering|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Subject(s):||Engineering, Electronics and Electrical|
|Abstract:||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.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1988.
|Date Available in IDEALS:||2014-12-15|
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Dissertations and Theses - Electrical and Computer Engineering
Dissertations and Theses in Electrical and Computer Engineering
Graduate Dissertations and Theses at Illinois
Graduate Theses and Dissertations at Illinois