Acoustic lens using extraordinary acoustic transmission
OwnerWilliam M. Robertsoninventor
Life of this patent
Estimating the term…
Abstract
An acoustic lens or diffractive acoustic device, including but not limited to, a sub-wavelength thickness lens or diffuser, comprising an array of Helmholtz resonators (HRs) that provide perfect or near-perfect sound transmission through a rigid barrier. HRs are arranged in a line or an array confined within a waveguide and oriented so that one neck protrudes onto each side of the barrier. Extraordinary acoustic transmission (EAT) occurs when radiation (such as EM or acoustic radiation) incident on the barrier perforated with sub-wavelength holes is transmitted at a rate higher than expected based on the areal coverage fraction of the holes. Transmission is independent of the direction of sound on the barrier and the relative placement of the necks.
Claims11
A device for modifying radiation, comprising:
- a barrier with a first side and a second side, wherein said barrier is opaque to radiation incident on the first side;
- and
- two or more Helmholtz resonators embedded in said barrier, each Helmholtz resonator comprising a central volume with a first neck extending from the central volume to a first opening on the first side of the barrier and a second neck extending from the central volume to a second opening on the second side of the barrier, wherein the first opening and second opening are smaller in diameter than a diameter or width of the central volume.
Dependencies are inferred from the claim text.