An uplink multiple beam concept for theater coverage

An uplink antenna concept for theater coverage using multiple beam antennas is described. Multiple beam antennas increase uplink capacity by using frequency reuse with the component beams. Protection from uplink interference is achieved by the narrow beamwidth of the component beams, and by an electronic beamsteering technique that aligns pattern nulls with interference sources close to desired signals. This interference protection versus the complexity of signal processing alternatives is a tradeoff to be evaluated in deriving a cost effective system design. This concept requires a larger uplink antenna design, and the inherent narrow beamwidths may require a ground beacon tracking to compensate for satellite attitude variations. Preliminary system sizing estimates are presented.