Improving the performance of fixed broadband beamformer using auxiliary elements

A novel technique for improving directivity pattern and for reducing the sidelobes of a uniform delay-and-sum (DS) broadband beamformer array is considered. This technique involves the addition of two auxiliary elements, which together produce a broadband cosine pattern used for pattern reconfiguration. The amplitude of the excitation and the distance between two elements of the auxiliary array controls the performance of the resulting broadband pattern. Thus, this technique can be easily implemented in real world. Simulation results, show that the proposed technique produces results that are significantly favorable than conventional broadband DS beamformer array. Moreover, the directivity pattern of the proposed technique has been improved over the entire frequency range of interest.