Antenna systems for future European broadcasting satellites

Future European broadcasting satellite systems call for higher system capacities and lower costs per channel than today's operating direct broadcasting satellites. Highly efficient illumination of the service areas has to be performed by well contoured antenna beams in order to use the spacecraft power resources economically. Several antenna systems for these purposes are presented. For elliptical beams the elliptically contoured reflector fed by an elliptical corrugated horn is the preferred single reflector solution. Special surface shaping of main and subreflector is an attractive alternative for an elliptical beam, if a dual reflector antenna can be accommodated on the spacecraft. Multifeed antennas with single or dual mode beam forming networks have to be employed for high gain illumination of contoured, overlapping multibeam coverages.