Patent ID: 7522124

Claim:
A compensating multi-layer material comprising: an indefinite anisotropic first layer having material properties of ε 1 and μ 1 , both of ε 1 and μ 1 being tensors, and a thickness d 1 ; an indefinite anisotropic second layer adjacent to said first layer, said second layer having material properties of ε 2 and μ 2 both of ε 2 and μ 2 being tensors, and having a thickness d 2 ; and, wherein ε 1 , μ 1 , ε 2 , and μ 2 are simultaneously diagonalizable in a diagonalizing basis that includes a layer normal to said first and second layers, and ɛ 2 = ψ ⁢ ⁢ ɛ 1 μ 2 = ψ ⁢ ⁢ μ 1 where φ = - [ d 1 d 2 0 0 0 d 1 d 2 0 0 0 d 2 d 1 ] and φ is a tensor represented in said diagonalizing basis with a third basis vector that is normal to said first and second layers.