Efficient computation of surface fields excited on an electrically large circular cylinder with an impedance boundary condition
Author(s)
Advisor
Altıntaş, AyhanDate
2006Publisher
Bilkent University
Language
English
Type
ThesisItem Usage Stats
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Abstract
An efficient computation technique is developed for the surface fields excited
on an electrically large circular cylinder with an impedance boundary condition
(IBC). The study of these surface fields is of practical interest due to its applications
in the design and analysis of conformal antennas. Furthermore, it acts
as a canonical problem useful toward the development of asymptotic solutions
valid for arbitrary smooth convex thin material coated/partially material coated
surfaces.
In this thesis, an alternative numerical approach is presented for the evaluation
of the Fock type integrals which exist in the Uniform Geometrical Theory of
Diffraction (UTD) based asymptotic solution for the non-paraxial surface fields
excited by a magnetic or an electric source located on the surface of an electrically
large circular cylinder with an IBC. This alternative approach is based
on performing a numerical integration of the Fock type integrals on a deformed
path on which the integrands are non-oscillatory and rapidly decaying. Comparison
of this approach with the previously developed study presented by Tokg¨oz
(PhD thesis, 2002), which is based on invoking the Cauchy’s residue theorem by
finding the pole singularities numerically, reveals that the alternative approach is
considerably more efficient. Since paraxial solution is a closed-form solution and
very efficient in terms of computational time, there is no need for an alternative
approach for the evaluation of the paraxial surface fields.