Line-integral representation of the Kirchhoff-type aperture radiation for a parabolic reflector

Reflector antenna analysis is typically performed by physical optics (PO); for simple shapes (i.e. parabolic reflectors), the combination of geometrical optics (GO) and Kirchhoff-type aperture integration (K-AI) provides an alternative scheme to evaluate near- to far-field contributions. In this paper a line-integral representation is presented for the field radiated by a parabolic reflector antenna illuminated by a focal axial symmetric feed-pattern with Huygens´ type polarization. This formulation provides a quite simple and physically appealing procedure to observe the field from near to intermediate region with a reduced numerical effort.