Acoustic Illusion Medium Mimicking Scattered Waves of a Groove on a Flat Surface Based on Transformation Acoustics

An acoustic illusion medium for mimicking a groove on a flat surface is designed by using the equivalent circuit models for full-tensor anisotropic acoustic metamaterials. The concept is explained according to the theory of transformation acoustics and its circuit parameters are calculated from the design formulas. The mimicking operations of the normal and the oblique incidence cases are shown by circuit simulations with a SPICE simulator to confirm the validity of the design theory. In addition, the radar cross sections (RCSs) are compared with those of the groove to evaluate the operations.