A Novel Technique for High-Performance Correction of Beam Aberration in Deep Space Antennas

Abstract

This letter presents a high performance technique for beam aberration correction in beam-waveguide (BWG) antennas. Beam aberration arises when high-gain ground-station antennas target spacecrafts moving not only along the antenna boresight, but also in the transversal direction. In this case, the antenna receives and transmits in slightly different directions, and, therefore a separation of the transmission and reception beams is needed. The novel algorithm has been developed in the case of European Space Agency (ESA) deep-space antenna 2, and consists in moving part of the lower beam-waveguide feed system. In particular, an ellipsoidal solid mirror is translated along three axes, and a feed horn is translated along one axis. The proposed methodology is validated by comparing its performance with two other techniques found in the literature, in terms of physical optics simulation results. It will be shown how the novel approach allows for higher beam separation, while keeping very low antenna gain degradation. Moreover, the required movements can be achieved with simpler and cheaper servo-mechanisms.