Practical supergrain head sized arrays

This paper carried out a new design of head sized sensor arrays with a simple delay-and-sum beamforming which provides useful amounts of directivity index with sufficient robustness to errors. A frequency-independent sidelobe reduction is proposed to achieve optimal frequency characteristics. In order to obtain this control, a principle of combining multiple level of array structures is established. Results are presented for spherically isotropic noise. It is found that good performance can be obtained for a head sized array by combining multiple level structures with simple delay and sum beamformer