Abstract: An antenna that radiates non-dispersive and time-aligned wave-fronts at all angles of radiation (in a half space). The antenna consists of a source radiator enclosed within a metallic shield with an aperture opening to couple plane waves radiated by the source through the aperture. Pulse dispersion is eliminated by having a truly planar aperture, resulting in an abrupt radiation zone, and the aperture field distribution being uniform. Wave-front alignment is caused by the continuity of the coupled electric field lines of force onto the metallic shield to result in radiated spherical waves. The antenna transfer function is impulse-like for all angles of radiation, thus it can be considered a distortion-less antenna.