Earth-station antennas for multiple satellite access

Antenna configurations are surveyed for simultaneously accessing a number of stellites from a single earth station. Both specially designed antennas and methods for upgrading existing antennas are discussed. A general treatment is presented, although emphasis is placed on the AUSSAT system of three satellites spaced at 4°. Results indicate that in this case specially designed multiple-access antennas are possible up to the largest antenna diameters needed. However, the upgrading of existing earth stations may be limited to reflectors of <5 m in diameter, even when sophisticated feed designs are used.