New class of primary-feed antennas for use with offset parabolic-reflector antennas

In many practical applications the performance of an offset parabolic-reflector antenna is limited by the offset reflectors´ depolarising and beam-squinting properties. The letter describes a new class of primary-feed antennas which overcome these limitations. The new primary-feed types offer a significant improvement in the crosspolar and beam-squinting properties of the offset reflector antenna, without adding significantly to the complexity or mass of the primary-feed system.