Rotman Lens Design With Wideband Dra Array

Nikkhah, Mohammad Ranjbar; Hiranandani, M.A.; Kishk, A.A.

doi:10.2528/pier20050801

Cited by 10 publications

(1 citation statement)

References 17 publications

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“…In the past few years, rapid development of metamaterials (Liu et al, 2000;Fang et al, 2006;Li et al, 2009;Toyoda et al, 2011;Christensen and de Abajo, 2012;Liang and Li, 2012;Quan et al, 2014;Cummer et al, 2016;Cheng et al, 2019; and metasurfaces (Li et al, 2013;Tang et al, 2014;Xie et al, 2014;Xie et al, 2017;Assouar et al, 2018;Holloway et al, 2019;Quan et al, 2019;Zhu and Assouar, 2019;Gao et al, 2020;Nikkhah et al, 2020) provides an unprecedented way to overcome the limits of conventional absorption materials and realize high absorption performance. These absorbing structures usually contain subwavelength resonant units to enhance energy density and dissipate sound energy inside.…”

Section: Introductionmentioning

confidence: 99%

Ultra-Thin Metasurface-Based Absorber of Low-Frequency Sound With Bandwidth Optimization

Guan

Sun

et al. 2021

Front. Mater.

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We report, both theoretically and experimentally, a type of ultra-thin metasurface-based low-frequency sound absorber with bandwidth optimization. Such a metasurface unit consists of an ultrathin resonator (thickness∼1/90 wavelength) with a circular hole on the upper panel and four narrow slits inside a multiple-cavity structure. Eigenmode simulations of the unit show rich artificial Mie resonances, in which a type of monopolar Mie resonance mode can be obtained at 238.4 Hz. Based on the excitation of the monopolar mode, we can realize the near-perfect low-frequency sound absorption with the maximum absorption coefficient and fractional bandwidth of 0.97 and 12.9%, respectively, which mainly arises from the high thermal-viscous loss around the circular hole and four narrow slits of the unit. More interestingly, by combining 4 units with different diameters of the circular hole, we further enhance the fractional bandwidth of the compound unit to 18.7%. Our work provides a route to design ultra-thin broadband sound absorbers by artificial Mie resonances, showing great potential in practical applications of low-frequency noise control and architectural acoustics.

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