LAUSR

This paper demonstrates the design of ultra-transparent anisotropic media for broadband acoustic invisibility. The required parameter distributions of the proposed invisibility cloak are derived by coordinate transformation, and its practical implementation simply consists of two-dimensional solid arrays in fluids. By studying the acoustic properties of the structures in the quasi-static limit, it is found that similar anisotropic features and transparent effects can be achieved with two kinds of structures, i.e., anisotropic solid cells arranged in the square lattice and cylindrical cells arranged in the highly anisotropic lattice. The acoustic impedance of the anisotropic cloaking media can be perfectly matched to the background fluid. The performances of the designs are quantitatively evaluated and compared in broadband by the averaged invisibility parameter. The full three-dimensional structure is also analyzed for demonstrating the practical feasibility of the scheme. The results show that the anisot...