A numerical method for designing acoustic cloak with homogeneous metamaterials

Based on the form invariance of Helmholtz equation, we present a rhombic acoustic cloak constructed with homogeneous metamaterials. In free space, the proposed cloak can effectively conceal an object inside under a given incident direction. Another application, namely carpet cloak, was also demonstrated by full wave simulations. The proposed cloak provided great convenience in the fabrication process due to the spatially uniform of relative density and modulus tensors.