Advanced Optimization of an Isoflux Reflectarray

This paper presents a method for the optimization of the cross-polar component of a circularly polarized isoflux reflectarray (RA) for payload data handling and transmission. The advanced optimization technique consists of an efficient lookup table parametrization employed in a direct radiation pattern optimization of the RA through minimax algorithms. The lookup table parametrization is employed in a spline projection of the RA cells distribution. The spline coefficients are modulated to achieve a sectorial bilateral isoflux radiation pattern with cross-polar discrimination superior to 15 dB. The RA optimization is performed by considering cells local periodicity that is naturally ensured by the spline projection of the RA layout.