Positionable satellite antenna with reconfigurable beam

摘要

An antenna, forming a part of an antenna system, is suitable for use on a communication satellite encircling the earth, and has a reflector illuminated by a set of feed elements wherein one of the feed elements generates a primary beam. The reflector is shaped to establish a specific configuration of the beam, and, upon illumination of the earth, there results a specific shape to the beam footprint. A mechanical positioning device connects the antenna with a body of the spacecraft for adjusting an orientation of the feed antenna and its beam relative to the body of the spacecraft. Control circuitry for adjustment of signal strengths and phase shifts of signals sent to respective ones of the feeds is accomplished by electronic circuitry including a memory which stores coefficients employed in the operation of variable power dividers and variable phase shifters of a feed network supplying electromagnetic signals to the feed. The memory is addressed to provide a desired correction to beam configuration corresponding to a specific orientation of the antenna.