Effects of metamaterial slab with negative permeability applied to magnetically-coupled wireless power transfer system

Effects of a metamaterial slab with negative permeability applied to a magnetically coupled two-loop wireless power transfer system on efficiencies are analyzed. Particularly, the maximum efficiencies are examined as a function of s/d (s: slab width, d: distance between two loops) and the slab loss tangent. They are evaluated in terms of coupling coefficients (k), effective Q-factors of the loop, and optimum loads for maximum efficiencies, considering the slab losses. Using the meta-slab, some enhance-ment of transfer efficiencies can be achieved when s/d ≈0.2 even for the case of considerable loss tangent of 0.2.