A Circularly Polarized Element for Reflectarray Antennas

This letter presents a scheme to generate circularly polarized waves in a reflectarray antenna. It originates with the design of a linearly polarized element, consisting of an aperture coupled patch with slot and line of variable length. Using this prototype, a circularly polarized element is then designed. The method used here is based on the finite element method (FEM) that uses the Floquet modal expansion theorem to approximate the infinite array model and not precise analysis of the array. This capability is found in the high frequency structure simulator (HFSS), and so we have used this software to achieve our goals.