DefinePK

Abstract

The importance of wide band nulling arise from the fact that the array pattern is frequency dependent and the direction of arrival of the undesired signal is not always located exactly. The proposed method for wide band nulling is based on the minimax approximation. The algorithm depends on finding a set of new phases to reject a wide sector in the side lobe while not seriously affecting the other pattern characteristics. The method combines the advantages of the phase only techniques and the flexibility of the minimax algorithm. The phase-only nulling can provide the pattern synthesis at lower cost while the Minimax provides the designer with the ability to control the null depth and the side lobe level to obtain an acceptable signal to interference noise ratio. The method is tested for both linear and planar arrays and is proved to be effective for any initial pattern. The disadvantage of this method is that it is not capable of obtaining two nulls symmetrically distributed around the main beam which is not considered to be a common practical case.