Optimal Annular Structures for Resonant Magnetic Wireless Power Receivers

Previous studies of flat, multi-turn spiral resonators have found that the effective series resistance may be reduced by splitting the conducting traces. [1] [2] In this paper, the special case of two-dimensional, single-turn, multi-annulus resonators with rotational symmetry is studied. Optimal inter-annulus gaps and annulus widths are found for resonators consisting of a fixed number of annuli and a fixed outer diameter. In addition, an optimal distribution of capacitance is found for bridging a radial gap in a wide annulus.