Ultra scanning geostationary orbiting radar: an array compensated spherical reflector antenna

Current advances in monitoring hurricanes and convective storms throughout their life cycles necessitate the development of technologies for high resolution spacecraft antennas with an ultra-scanning capability. Therefore for the first generation of geostationary orbiting radars, an antenna system is to be designed at 35 GHz. The feasibility of correcting phase aberration of spherical reflector antennas with planar array feeds is investigated. A synthesis procedure for the array excitation is developed which invokes the reciprocity theorem and phase conjugate matching. Using the synthesized compensating array-feed, the radiation characteristics of a compensated spherical reflector is simulated for both focus and 4° scan cases and results are compared with the uncompensated case to show performance improvement.