Null steering in phased arrays by controlling the positions of selected elements

A new technique is presented that is capable of steering nulls in the antenna pattern in the directions of strong interference signals without affecting the main beam. The technique is based on the element position perturbations of selected elements of the antenna array. This technique frees the phase shifters to be used solely for steering the main beam toward the direction of the desired signal. It also freezes the positions of those elements that have insignificant contributions to the nulls. Our results have shown to be comparable to the results obtained from the method of controlling the positions of all elements.