Reflector antenna having varying reflectivity surface that provides selective sidelobe reduction

摘要

A composite antenna reflector architecture for improving beam-to-beam isolation in a multi-spot illuminated reflector antenna employs a plurality of annular rings surrounding a central reflective dish and having respectively different controlled reflectivity profiles. The reflectivity-tailored reflector rings alter illumination taper and reduce selected sidelobe energy, and minimize degradation in coverage performance and gain slope in the radiation profile of the antenna. A respective ring employs a frequency selective surface laminate of layers containing different elements that resonate at different frequencies spectrally spaced to provide at least one composite frequency response characteristic.