Sidelobe Reduction in Offset Dish Parabolic Antennas Using Metallic Scatters

Offset feed antennas are most commonly used for satellite applications, where very high gain is needed. The benefit of the offset configuration is that it positions the feed horn away from the dish itself so that it does not cast a shadow on the dish. However, this yields to bigger sidelobes which results in a significant interference problem especially between adjacent antennas. Adding metallic scatters (strips) to the antenna at specific positions and with specific dimensions and shapes would significantly minimize the sidelobe level and consequently enhance its directional characteristics. A detailed analysis of the suggested design was performed based on a huge series of electromagnetic simulations and testing experiments, which have clearly demonstrated a sidelobe reduction of about 10 dB.