Equivalent Circuit Models for Two-dimensional Full-tensor Anisotropic Acoustic Metamaterials

We extend the theory of equivalent circuit models for two-dimensional (2-D) full-tensor anisotropic electromagnetic metamaterials and introduce the design method with equivalent circuit models to designs of 2-D full-tensor anisotropic acoustic metamaterials. Relations of circuit parameters and material parameters including the off-diagonal components of the mass density tensor are revealed from the duality of circuit equations and acoustic equations. A 2D acoustic carpet cloak for hiding a bump on a flat surface is designed with equivalent circuit models to confirm the validity of the theory. Circuit simulations are carried out and the voltage distributions and the radar cross sections are compared with those for the cases with the flat surface and the bump. Those results show the angle independent cloaking operations of the designed acoustic carpet cloak.