@article {Kim:2020:0736-2935:195, title = "Acoustic metalens with broadband high transmission under consideration of visco-thermal losses and elastic deformation", journal = "INTER-NOISE and NOISE-CON Congress and Conference Proceedings", parent_itemid = "infobike://ince/incecp", publishercode ="ince", year = "2020", volume = "261", number = "6", publication date ="2020-10-12T00:00:00", pages = "195-199", itemtype = "ARTICLE", issn = "0736-2935", url = "https://ince.publisher.ingentaconnect.com/content/ince/incecp/2020/00000261/00000006/art00025", author = "Kim, Chankyu and Jeon, Wonju", abstract = "We propose an acoustic metalens with broadband high transmission. The lens is a planar gradient-index lens consisting of cuboid-shaped unit structures with different refractive indices from 1.07 to 1.98. Each unit structure has a symmetric coiled channel whose cross-sectional area is gradually varying. The cross-sectional area of channels is determined for the unit structures to have high transmittance in a broad frequency range. The transmittance of the unit structures and focusing capability of the designed metalens are investigated with consideration of visco-thermal losses and elastic deformation of the structures. The transmittance of the unit structure is higher than 0.8 in a target frequency range of 2.5-5.5 kHz and the acoustic intensity is significantly amplified by the lens in the frequency range.", }