Broadband acoustic concentrator with multilayered alternative homogeneous materials.

A two-dimensional cylindrical acoustic concentrator is designed with multilayered alternative homogeneous materials, which can focus acoustic field and enhance acoustic energy in a given area. The frequency response analysis of the acoustic concentrator demonstrates that the acoustic energy can be concentrated within the device over a wide frequency band. Meanwhile, there are contradictory relations between the acoustic concentrating performances in the inner region and the scattering properties in the outer region of these concentrators. When the contradictory relations satisfy compromise balance, the concentration ratio can reach at least 70%.