RECONFIGURABLE REFLECTOR ANTENNA PRODUCING PATTERN NULLS

The paper reports how a reconfigurable mesh reflector antenna can be u sed to generate nulls in its radiation pattern while closely maintaini ng the original pattern in regions away from the null. The theory is d eveloped and theoretical results are presented for a typical antenna o f a size suitable for spacecraft applications. Experimental results, w hich are in close accord with theory, are given for an offset mesh ref lector which is scaled to approximately 30 wavelengths in diameter and is fed by a corrugated horn. It is shown that deep nulls can be forme d both within the mainbeam and within the side-lobe region. Applicatio ns of the offline mode of operation lie where there: is a priori knowl edge of the location of the interfering source, which could be the cas e in civil scenarios, including those of some deep-space missions requ iring communication with an earth-based transmitter.