Recent activities in beamformers for space applications

The European Space Agency has been developing antenna technologies to meet near term and longer term mission requirements in L-band for mobile satellite systems, in C- and Ku-band for broadcast and fixed satellite services and more futuristic Ka-band systems for the same. These systems require fixed contoured beam antennas, multiple contoured beam antennas or multi-spotbeam antennas. Future requirements are tending towards more flexible high performance systems where the beamforming system and its pre-qualification is key in meeting the higher power levels and more complex channel to beam allocations requested. In many cases, the Agency´s pre-development activities have led to “flight ready technologies” for commercial satellites. The authors concentrate here on classical contoured beam antennas, multiple contoured beam antennas, reconfigurable beam antennas and finally with application to L-band semi-active antennas. They discuss beamforming via a network, although the derivation of contoured and multiple contoured beams using a shaped reflector system is also possible and is currently receiving attention