The synthesis of offset dual reflector antennas by genetic algorithms

Abstract

Reflector antennas have various applications in radar, microwave telecommunication, remote sensing and radio-astronomy systems. Although there are applications in which shaped reflector antennas are used, most applications use the classical parabolic reflectors. Therefore, the design of an optimized reflector is of great importance. We present a new method for the far field pattern synthesis of parabolic reflector antennas that can virtually optimize all major design parameters simultaneously. The direct problem is formulated using the equivalent paraboloid technique with the far field pattern computed based on high frequency geometrical optics (GO) and/or physical optics (PO) approximations, depending on the desired speed and accuracy. The inverse problem is formulated based on an optimization of the geometrical parameters of the antenna using a simple genetic algorithm (see Goldberg, D., 1989). The proposed design method optimizes the gain and the cross-polarization of the radiation pattern of the reflector antenna. It also satisfies the FCC standard limits on the sidelobe level envelope.