Abstract: An antenna system for satellite applications is provide, the antenna system comprising an antenna array and a feed structure, and the antenna array is a passive antenna array configured to have a first state and a second state, the second state being a first deployed state. The feed structure is configured to provide a linearly polarized incident field for the antenna array in the first deployed state. The antenna array comprises a plurality of array elements, and the plurality of array elements forms a polarization conversion surface configured for converting the linearly polarized incident field to a reflected/transmitted circular polarized field. The antenna array is configured so that the radiation pattern of the reflected/transmitted circular polarized field corresponds to a predetermined radiation pattern and an array element geometry and an array element position of each of the plurality array elements are configured to provide the predetermined radiation pattern.