Application of retrodirective beams to achieve low sidelobe levels in small phased arrays

Synthesis of beams with low sidelobe levels is a difficult problem for the case of small phased arrays with few elements. Mutual coupling between elements means that conventional weighting algorithms are not applicable. A technique is presented that calculates a complex weight vector for a five element linear array, giving a reduced sidelobe beam pattern. Sidelobes are reduced by the addition of retrodirective beams to the quiescent beam pattern. No knowledge of the coupling coefficients or element radiation patterns is required.