Line integral representation of physical optics scattering from a perfectly conducting plate illuminated by a Gaussian beam modeled as a complex point source

An exact line integral representation of the physical optics fields scattered by a perfectly conducting plate illuminated by a vector complex point source is derived. Complex point sources provide, in the paraxial region, an accurate model of Gaussian beams, and can thus be used to efficiently represent the pattern of directive sources. Numerical results are shown to illustrate the exactness of the procedure and the computation time saving is investigated by comparison with surface integration. Moreover, by analyzing the scattering from a plate illuminated by a corrugated circular horn, the feasibility and accuracy of the proposed approach for modeling scattering due to real sources are demonstrated.