Study of sensor positions for broadband beamforming

Recently, a sensor delay-line (SDL) based array structure was proposed for broadband beamforming. It is similar in form to the traditional narrowband beamformer, the only difference being a re-arrangement of the sensor positions according to the SDL concept. However, it is well-known that the narrowband beamformer can perform broadband beamforming to some degree, which gives rise to the question of whether this new arrangement is superior to the narrowband approach or not. The aim of this work is to answer this question by providing a detailed study of sensor positions for broadband beamforming. We show that when the bandwidth exceeds some threshold value, the SDL beamformer significantly outperforms the narrowband beamformer, which well justifies the new structure and gives a clear endorsement to the SDL concept.