A Prototype Digital Beamforming Antenna for Future Satellite Communications

In this paper a fully adaptive digital beamforming antenna system for receiving in the L-Band is described. The system consists of a 25-element planar array for circular polarisation, 25 parallel receiving channels realising a double down-conversion to the base band or a very low frequency, a multiplexer followed by a state-of-the-art A/D-converter-card and a fast PC for the processing of the received signals. This allows the highest degree of flexibility for various tests of different digital beamforming algorithms. The different subunits of the array system and the overall antenna system design is explained in conjunction with the special demands due to an application in future satellite communications. The demonstration system is used to obtain experience in digital beamforming technology and to investigate and evaluate different beamforming algorithms. As an additional objective of the work, a performance demonstration in the communication environment of LEO-satellites is scheduled.