Patent ID: 6650281
Filing Date: 2003-11-18
Classification: H01Q

Abstract:
A multi-beam receive or send antenna for a geosynchronous satellite of a telecommunications system intended to cover a territory divided into a plurality of areas, a beam intended for each of said plurality of areas being defined by a plurality of radiating elements, or sources, disposed in the vicinity of the focal plane of a reflector,the antenna including means for modifying the locations of the areas or for correcting antenna pointing errors, the antenna including a first series of first Butler matrices, disposed in parallel planes, and a second series of first Butler matrices also disposed in parallel planes but in a direction different from that of the first series, to enable the displacement of the beams over said areas or the correction of said pointing errors in two different directions, and therefore in all directions of the area covered by the antenna, each input of each first Butler matrix of said first series being connected to a radiating element, and each output of each first Butler matrix of said second series being connected to a corresponding input of an inverse Butler matrix via an amplifier, in a set of amplifiers, and a phase-shifter, wherein said means for modifying includes said phase-shifter, the outputs of the inverse Butler matrices being associated with a beam-forming network, and wherein the phase-shifters displace the beam over a plurality of areas or correct said pointing errors, each first Butler matrix and inverse Butler matrix distributing the energy received by each radiating element over said set of amplifiers so that the effect of failure of one amplifier is uniformly distributed over all the output signals, at least one radiating element being connected to an input of one first Butler matrix of said first series and to an input of another first Butler matrix of said first series.