Antennas for INMARSAT III and beyond

INMARSAT has placed a contract for the procurement of a third generation spacecraft system to fulfil the communications requirements of mobile terminal users worldwide into the 21st century. The authors describe the system requirements for the INMARSAT III spacecraft to service the projected communications capacity needs, focussing upon the L-band antenna system requirements which are one of the key technology development areas of the programme. The critical technology aspects of the antenna design needed to provide efficient implementation of the system requirements are discussed