Sensitiveness of cloaking performance on moderate material parameter violation

A coordinate transformation approach dictates inhomogeneous and anisotropic medium in cloaks' design. In this paper, the sensitiveness of different cloaking schemes based approximate cloaks, in which the EM parameters are limited to a range more plausible to realize, is investigated. When devising the cloak using dispersive lossy metamaterials, the unavoidable deviation in material parameters degraded the cloak's performance significantly, especially in terms of bandwidth. Numerical experiments show that the imperfect cloak under moderate compression presents low anisotropy and is a candidate scheme more insusceptible to moderate changes in EM parameters.