Steerable Multibeam Reflector Antenna for Space Application

With the rapid development of satellite communication technology, the current multibeam antenna with fixed predefined coverage cannot meet the increasing demand for high-capacity and high-flexible communication systems. In order to meet this demand, this paper proposes a steerable multibeam reflector antenna with better coverage scanning performance than traditional multibeam antenna. And the design method is described, including antenna configuration, antenna steerage, feed reusing scheme, and beam optimization method while coverage scanning. In order to verify the improvement of the beam scanning performance by using the design method in this paper, a K-band steerable multibeam reflector antenna prototype is designed, fabricated, and simulated. The design results show that no deterioration of the radiation performance during the beam scanning is achieved. Finally, the proposed steerable multibeam reflector antenna prototype is measured in the anechoic chamber. The measurement result shows that the simulation and measurement agree very well on the scale-in prototype, which shows that the proposed steerable antenna is feasible. By updating the amplitude and phase excitation coefficient in the beamforming network to the optimal value while steering, the antenna proposed in this paper can improve beam gain by 1.5 dB, while suppressing the side lobe level of an additional more 10 dB. This design method can provide design theoretical methods and key technical support for future flexible multibeam spaceborne antennas.