Near-zone electric field computation of a horizontal semi-infinite wire above earth
AuthorBudihardjo, Arifin, 1968-
AdvisorDvorak, Steven L.
MetadataShow full item record
PublisherThe University of Arizona.
RightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
AbstractAsymptotic expressions are obtained for the electric field due to a current propagating on a horizontal semi-infinite wire above the earth. First, exact integral representations are derived for the electric field due to a current on a semi-infinite wire in a general multi-layered medium. The resulting integral expressions are then specialized for the problem of a semi-infinite wire above the earth. The resulting expressions involve a semi-infinite integration over an integrand containing the incomplete Lipschitz-Hankel integrals. The steepest descent technique is applied to the direct and reflected terms separately, thereby providing a far-zone approximation for the field (E α r⁻¹). A recurrence relationship is then developed which allows the r⁻² term in the asymptotic expansion to be computed from the previously computed r⁻¹ term. A numerical comparison between the following three methods is carried out: numerical integration, one-term (1/r) approximation, and two-term (1/r²) approximation. It is shown that two-term solution yields more accurate results than that of the one-term solution, especially when the problem of a finite length wire above the earth is considered. The two-term expansion provides accurate results for the fields when 0.1 λ < r < ∞ and it consumes much less computation time than the numerical integration solution.