The present invention regards an antenna system comprising a reflection system that comprises a reflector having a rotational symmetry with respect to an axis of symmetry. Moreover, the antenna system also comprises an electronically steerable planar radiating array that is arranged in a focal region of the reflection system, has a rotational symmetry with respect to the axis of symmetry and is operable to radiate a primary radiofrequency beam oriented in a predefined direction of illumination with respect to the axis of symmetry in such a way as to cause a specific region of the reflector to be illuminated by said primary radiofrequency beam. Said specific region of the reflector is designed, when illuminated by said primary radiofrequency beam, to generate by reflection a secondary radiofrequency beam oriented in at least one predefined direction of transmission with respect to the axis of symmetry.