Method for reducing cross-polar degradation in multi-feed dual offset reflector antennas

摘要

A unique feed structure for improving the cross-polarization performance of a reflector antenna system (10) is disclosed. According to the present invention, the feed structure is an array (22) including a number of feeds (40, 45, 55, 60, 65, 70, 75, 80), which are rotated in a predetermined fashion to yield superior cross polarization performance of the antenna system. The array feed (50) in the center of the feed structure is positioned approximately in the focus of the antenna reflector (18). The array feeds located on the y-axis (40, 45, 55, 60) are slightly rotated in either a clockwise or a counterclockwise manner. The magnitude of the rotation is proportional to the distance of the feeds (40, 45, 50, 60) from the x-axis along the y-axis. The rotation of the feeds (40, 45, 55, 60) yields significant performance in cross polarization performance, while having little or no co-polarization effect.