Integral equation anlaysis of an arbitrary-profile and varying-resistivity cylindrical reflector illuminated by an E-polarized complex-source-point beam
Author
Oguzer, T.
Altintas, A.
Nosich, A. I.
Date
2009-06-09Source Title
Journal of the Optical Society of America A
Print ISSN
1084-7529
Publisher
Optical Society of America
Volume
26
Issue
7
Pages
1525 - 1532
Language
English
Type
ArticleItem Usage Stats
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Abstract
A two-dimensional reflector with resistive-type boundary conditions and varying resistivity is considered. The
incident wave is a beam emitted by a complex-source-point feed simulating an aperture source. The problem is
formulated as an electromagnetic time-harmonic boundary value problem and cast into the electric field integral
equation form. This is a Fredholm second kind equation that can be solved numerically in several ways.
We develop a Galerkin projection scheme with entire-domain expansion functions defined on an auxiliary circle
and demonstrate its advantage over a conventional moment-method solution in terms of faster convergence.
Hence, larger reflectors can be computed with a higher accuracy. The results presented relate to the elliptic,
parabolic, and hyperbolic profile reflectors fed by in-focus feeds. They demonstrate that a partially or fully resistive
parabolic reflector is able to form a sharp main beam of the far-field pattern in the forward half-space;
however, partial transparency leads to a drop in the overall directivity of emission due to the leakage of the
field to the shadow half-space. This can be avoided if only small parts of the reflector near the edges are made
resistive, with resisitivity increasing to the edge.