Magnetic superlens-enhanced inductive coupling for wireless power transfer

TL;DR

This paper demonstrates through numerical and analytical models that a negative-permeability superlens can significantly enhance wireless power transfer by focusing magnetic flux, even with realistic losses and geometries.

Contribution

It introduces a numerical approach to analyze magnetic superlens effects on wireless power transfer, validating the potential for improved coupling with practical considerations.

Findings

Magnetic superlens greatly enhances coil coupling.

Performance remains robust despite material losses.

Numerical results align with analytical predictions.

Abstract

We investigate numerically the use of a negative-permeability "perfect lens" for enhancing wireless power transfer between two current carrying coils. The negative permeability slab serves to focus the flux generated in the source coil to the receiver coil, thereby increasing the mutual inductive coupling between the coils. The numerical model is compared with an analytical theory that treats the coils as point dipoles separated by an infinite planar layer of magnetic material [Urzhumov et al., Phys. Rev. B, 19, 8312 (2011)]. In the limit of vanishingly small radius of the coils, and large width of the metamaterial slab, the numerical simulations are in excellent agreement with the analytical model. Both the idealized analytical and realistic numerical models predict similar trends with respect to metamaterial loss and anisotropy. Applying the numerical models, we further analyze the impact of finite coil size and finite width of the slab. We find that, even for these less idealized geometries, the presence of the magnetic slab greatly enhances the coupling between the two coils, including cases where significant loss is present in the slab. We therefore conclude that the integration of a metamaterial slab into a wireless power transfer system holds promise for increasing the overall system performance.