Separate phased feeds for correcting spherical aberration

Requirements for a radiation pattern of a spherical reflecting antenna determine a permissible phase error over the illuminated aperture. In order to extend an illuminated range of the aperture plane with a permissible phase error, several added separate phased feeds (located beyond the axis of a spherical reflector) with the necessary parameters are suited. The numerical analysis (by means of geometrical optics) of a phase error at the aperture plane as a function of the deep of a spherical reflector for the added phased feed located beyond the axis was carried out and the results are presented graphically.