Zooming techniques for a gregorian confocal dual reflector antenna

Reflector antenna pattern reconfigurability has been identified as a one of the most interesting and challenging area for satellite telecommunications. Steering and zooming the heard are important capabilities for onboard antenna configurations. This work presents a comparison between two different zooming techniques of a Gregorian confocal dual reflector antenna (GCDRA) when it scans electro-mechanically. The first of the zooming techniques consist of introducing a controlled quadratic path error (QPE) at the main reflector aperture, whereas the second technique is based on reducing the radiating aperture (RRA) of the antenna to a specified percentage.