Simple compensation for lateral misalignments in resonant inductive coupling links

This Letter describes a simple compensation method to reduce the transfer efficiency variation in a resonant inductive coupling (RIC) wireless power transfer link subject to lateral misalignment. The technique is based on impedance matching an RIC link such that the link operates at either over-coupling or critical coupling within the extents of lateral misalignment. Applying the method in a test scenario led to a reduction in the range of obtained transfer efficiency values, from 45% of peak value in a conventional arrangement, to 5%. The proposed method has a potential for application in the design of free-positioning planar wireless chargers.