A cloak scheme insusceptible to the change of material properties

An electromagnetic cloak based on a coordinate transformation approach is always inhomogeneous and anisotropic. In this paper, we investigate the sensitiveness of different cloaking schemes, when EM parameters are limited to a range more plausible to realize. Numerical experiments show that the imperfect cloak under moderate compression presents low anisotropy and is a candidate scheme more insusceptible to changes in EM parameters. When devising the cloak using dispersive lossy metamaterials, the unavoidable deviation in material parameters favors a lower anisotropic model such as the imperfect cloaking model.