A multi-element primary source and the associated commutation matrix for a communication satellite functioning in the TDMA mode

A multi-element primary source for the broadcast antenna of a multiple access communication satellite is described. The feeds are multiple pencil horns controlled by the TDMA electronics to give sequential zonal ground coverage. The parabolic reflector is fed by seven elements radiating with circular polarization. The number of radiating elements is proportional to the size of the zone covered. A test model of the system has performed sufficiently well so that a minimum directivity of 46 dB, a 1.35 deg coverage and a 4-5 dB improvement over previous large area coverage telecommunications satellites are expected with an on-station system.