Cylindrical cloak with axial permittivity/permeability spatially invariant

In order to reduce the difficulties in the experimental realizations of the cloak but still keep good performance of invisibility, we proposed a perfect cylindrical invisibility cloak with spatially invariant axial material parameters. The advantage of this kind of cloak is that only ρ and φ components of μ (or ε) are spatially variant, which makes it possible to realize perfect invisibility with two-dimensional metamaterials. The effects of perturbations of the parameters on the performance of this cloak are quantitatively analyzed by scattering theory. Our work provides a simple and feasible solution to the experimental realization of cloaks with ideal parameters.