Future trends in antennas for satellite applications

The trend in antennas for communication satellite systems has been to smaller terminals with correspondingly larger antennas on the satellite and the point-to-point system emphasizes this trend. Similar requirements can be observed in mobile communication and remote control systems and for scientific missions. Consideration is given to upper limits of the antennas size, beamwidths, profile errors, beam pointing, and test requirements. Several techniques need to be developed: the multi-element feed and associated feed network; the RF-sensing technique; and the highly accurate unfurlable reflector. While antennas larger than 30-50 m in diameter can be assembled in space, by means of a Shuttle-mounted manipulator, there is a trend against the use of large structures as reflectors. Instead, the structure will be built up of sub-units which can be steered individually (the Solar Power Satellite transmitting antenna).