Optimum shaping technique for advanced dual-gridded shaped reflectors

Current and proposed satellite communications systems demand dual-linearly polarised transmit-receive antennas for contoured and/or multiple beam coverages. The proven means of satisfying these requirements is by the use of dual-gridded parabolic reflectors with two separated feed arrays radiating opposite linear polarizations. The two parabolic dishes are gridded in perpendicular directions and placed in front of one another with independent focal points to maintain separated the relevant feed arrays and beamforming networks. This paper describes the results of an activity performed on the design of large and highly-shaped dual-gridded reflector antennas. The critical aspects in developing a reflector shaping technique based on an optimization algorithm are discussed. The advantage in compensating for the effects of reflector thermal distortions during the electrical antenna design are also demonstrated. This novel technique allows a less critical thermal control of the reflector assembly, with a consequent reduction of the development time, hardware mass, and ohmic losses