Antenna system electromagnetic lens arrangement

An antenna system comprises: a cylindrical electromagnetic lens 1 with at least one variation in dielectric permittivity and a dielectric member 2 receiving an output beam 11 from the cylindrical lens 1 and focusing the beam in an elevation plane perpendicular to the planar face of the cylindrical lens 1. The dielectric member 2 may be ring shaped and at least partially surrounds the cylindrical lens 1 which has first and second cylindrical surfaces of respective diameters. The second surface of the dielectric member may face a lateral face of the cylindrical lens 1. The dielectric member 2 may be detachably mounted in the antenna system and have a height which is larger than the axial thickness of the cylindrical lens 1. The dielectric member 2 may be made of PTFE with a relative permeability of between 1.5 and 2.5. At least one waveguide signal feed may be located at the circumference 5 of the cylindrical lens 1. A conductive mounting may be integrated with the lens and the feed circuit. A shielding enclosure may be made of a metallic material or of a moulded plastic material or a ceramic material which has been metallised. The antenna system may provide beamsteering with azimuth and elevation control.