High-frequency green´s function for a sectoral array of electric dipoles on a grounded slab

A uniform, high-frequency solution is presented for the electromagnetic field radiated at finite distance by a sectoral array of elementary dipoles placed on an infinite grounded dielectric slab. Our attention is focused to give an efficient asymptotic representation for observation point laying on the array plane, where boundary conditions are applied. This solution is useful for the efficient analysis of large finite printed arrays. The field is represented in terms of a series encompassing propagating and evanescent truncated Floquet waves together with their corresponding diffracted rays, which arise from the edges and the vertex of the array. The diffracted waves contain discontinuities which compensate the disappearance of surface wave and truncated Floquet waves at their pertinent shadow boundaries.