A multi-beam telecommunications antenna system with a focusing device including a two-dimensional radiator array generating a plurality of beams simultaneously by setting amplitude-time parameters of the signals for each radiator. The antenna includes: a focusing system having an amplifying lens; a radiating device, for irradiating the amplifying lens and having a two-dimensional radiator array, is disposed at a distance from the amplifying lens and covers a projection area of beams at this distance; and a beam forming system. At least one sub-array of the radiators provides a beam in a set direction. For each beam, the beam forming system provides, for each radiator in the corresponding sub-array, amplitude-time parameters of the signal being transmitted to form a non-planar wavefront, which is equidistant across the amplifying lens to a planar wavefront of the beam. The radiating surface of the radiator array is outside a region of self-intersection of the non-planar wavefronts.