Asymptotic evaluation of the edge diffraction in cylindric paraboloidal reflector antennas

Abstract

Diffraction fields on the edge of a cylindrical parabolic reflector antenna are examined. Firstly canonical problem is defined for the edge of the antenna and study is reduced to a half plane scattering problem. Coordinate system is defined as the origin being the edge of the reflector, so the feed became offset. Space is divided into two parts according to ρ and edge diffracted fields are calculated for the region where ρ ≤ ρ0. Obtained poorly divergent series are changed into complex integrals for k→∞ and these integrals are Solved in the same conditions. Uniform expression of edge diffracted field is calculated by using Fresnel integrals.