Files in this item
|(no description provided)|
|Title:||Spectral-domain analysis of finite-frequency selective surfaces|
|Author(s):||Merewether, Kimball Olan|
|Doctoral Committee Chair(s):||Mittra, Raj|
|Department / Program:||Engineering, Electronics and Electrical|
|Discipline:||Engineering, Electronics and Electrical|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Subject(s):||Engineering, Electronics and Electrical|
|Abstract:||Though frequency selective surfaces have been investigated for over two hundred years, accurate numerical analysis of these surfaces is still in its infancy. Past models assumed that the surface is periodic, infinite in extent, and illuminated by a uniform plane wave. In many practical applications, however, these assumptions may be invalid. In this thesis, the method of moments is applied in the spectral domain to model finite frequency selective surfaces, to study the effects of non-plane-wave sources, and to explore the advantages of gradually adjusting the lattice and shape of the element in a nonuniform frequency selective surface for non-plane-wave excitation.
In pursuing these goals, the following topics are discussed in some detail. First, because of the limited interest in free-standing surfaces, and because the usual cascade approach is not applicable to finite frequency selective surfaces, a general multilayer Green's function is developed in order to incorporate an arbitrary dielectric support. Second, because the analysis of finite arrays can be computationally intensive, several strategies are discussed for efficiently filling the matrices generated by the application of the spectral-domain method of moments. Third, a few methods for handling the singularities of the spectral Green's function are briefly mentioned, including a comparison of several adaptive numerical integration routines for integrating functions which are singular or sharply peaked.
The effects of finite dimensions are evaluated by comparing the induced currents and reflection coefficients for the finite and periodic arrays. The effects can be classified into at least two frequency regimes. At frequencies that are near the first resonant frequency of the element, the edge plays a relatively minor role in influencing the scattered fields. At lower frequencies, an edge-to-edge resonance can be excited on the array, which cannot be predicted by periodic models.
|Rights Information:||Copyright 1989 Merewether, Kimball Olan|
|Date Available in IDEALS:||2011-05-07|
|Identifier in Online Catalog:||AAI9010957|
This item appears in the following Collection(s)
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