Trucco A, Traverso F, Crocco M
Department of Electrical, Electronic, Telecommunications Engineering and Naval Architecture (DITEN), University of Genoa, Via Opera Pia 11, 16145 Genova, Italy
Pattern Analysis and Computer Vision, Istituto Italiano di Tecnologia (IIT), Via Morego 30, 16163 Genova, Italy
J Acoust Soc Am. 2014 Jun;135(6):EL331-7. doi: 10.1121/1.4879674.
Linear arrays steered to end-fire provide superdirective robust performance if a constraint is imposed on the white-noise gain. Filter-and-sum beamformers achieve the maximum constrained directivity by tuning their complex weights over the frequency. Delay-and-sum beamformers have simpler structures, but their weights are fixed and optimized at a given frequency. This letter investigates the constrained directivity provided over a broad band by different delay-and-sum techniques. Complex weights and analytic signals attain near-optimal broadband performance over four octaves. Oversteered arrays using real weights and signals were found to attain superdirective performance over approximately two octaves. Hearing aids and directional hydrophones are potential applications for the considered arrays.
如果对白噪声增益施加约束，转向端射的线性阵列可提供超指向性稳健性能。滤波器求和波束形成器通过在频率上调整其复权值来实现最大约束方向性。延迟求和波束形成器结构更简单，但其权值是固定的，并在给定频率下进行了优化。本文研究了不同延迟求和技术在宽频带上提供的约束方向性。复权值和解析信号在四个倍频程上实现了接近最优的宽带性能。发现使用实权值和信号的过转向阵列在大约两个倍频程上实现了超指向性性能。助听器和定向水听器是所考虑阵列的潜在应用。
