title: Broadband performance of superdirective delay-and-sum beamformers steered to end-fire.
abstract: 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.
authors.affiliation: Department of Electrical, Electronic, Telecommunications Engineering and Naval Architecture (DITEN), University of Genoa, Via Opera Pia 11, 16145 Genova, Italy trucco@dibe.unige.it, federico.traverso@ginevra.dibe.unige.it.
authors.forename: A
authors.initials: A
authors.lastname: Trucco
authors.affiliation: Department of Electrical, Electronic, Telecommunications Engineering and Naval Architecture (DITEN), University of Genoa, Via Opera Pia 11, 16145 Genova, Italy trucco@dibe.unige.it, federico.traverso@ginevra.dibe.unige.it.
authors.forename: F
authors.initials: F
authors.lastname: Traverso
authors.affiliation: Pattern Analysis and Computer Vision, Istituto Italiano di Tecnologia (IIT), Via Morego 30, 16163 Genova, Italy Marco.Crocco@iit.it.
authors.forename: M
authors.initials: M
authors.lastname: Crocco
mesh_terms: D000162:Acoustics / Q000295:instrumentation*; D004867:Equipment Design; D006310:Hearing Aids; D016014:Linear Models; D009038:Motion; D012815:Signal Processing, Computer-Assisted; D013016:Sound; D013997:Time Factors; D014159:Transducers