Patent ID: 8344945
Filing Date: 2013-01-01
Classification: H01Q,H04B

Abstract:
1. A method of beam-forming for an antenna of a telecommunications spacecraft, the antenna comprising a phased array antenna, and the antenna providing a plurality of communications beams within a predefined geographical region, the method comprising: providing the phased array antenna as a plurality of antenna elements, each antenna element having an antenna element signal having a phase relationship and an amplitude relationship to the other element signals, and partitioning said antenna elements into a plurality of overlapping sub-arrays, each sub-array comprising a subset of all the antenna elements of the phased array, and at least some or all the antenna elements participating in more than one sub-array, allocating to elements of each sub-array respective intra sub-array beam-forming weights, and allocating to each sub-array respective main beam-forming weights for said plurality of communications beams such that the composite radiation pattern of the antenna provides said plurality of communications beams within said region, wherein a desired antenna directivity value for the plurality of communications beams is determined by an optimisation process, involving changing, in iterations, of said intra sub-array beam-forming weights, together with determination of main beam-forming weights for said beams at each said iteration.