• Media type: E-Article
  • Title: Random versus regular square lattice experimental comparison for a subwavelength resonant metasurface
  • Contributor: Lott, Martin; Roux, Philippe
  • Published: Acoustical Society of America (ASA), 2021
  • Published in: The Journal of the Acoustical Society of America, 149 (2021) 5, Seite 3645-3653
  • Language: English
  • DOI: 10.1121/10.0005060
  • ISSN: 0001-4966; 1520-8524
  • Keywords: Acoustics and Ultrasonics ; Arts and Humanities (miscellaneous)
  • Origination:
  • Footnote:
  • Description: An experimental comparison is reported here between two equivalent resonant subwavelength metasurfaces made of long aluminum beams glued closely together on a thin aluminum plate. One metasurface has a random distribution of the resonator beams, and the other has a regular square lattice of pitch 1.5 cm. The random lattice shows the “resonant” behavior of a typical metasurface, with a wide full bandgap for the first A0 Lamb mode. Instead, the regular square lattice combines Fano resonance with Bragg scattering at the edges of the passband, thus creating anisotropy and a pseudo bandgap. Comparisons with numerical simulations are performed, with good agreement with the experimental data. The multimodal response of the beams is also responsible for double negativity in a narrow frequency band, and the event of a pseudo bandgap around this same flexural resonance. In addition, the scattering regimes for both the random and regular metasurfaces are characterized using coherent and incoherent signal analysis.