Modeling and experimentation of misalignment-tolerable loosely-coupled coil structure

The misalignment of the transmitting and receiving coils in a wireless inductive link can degrade the link efficiency and limit the amount of power transfer. A coil structure, which is composed of two orthogonally-placed windings for the receiver, will be presented. Such structure lessens the variation of the coupling between the transmitting and receiving coils under coil misalignment. A canonical model for describing the interactions between the transmitting and receiving coils will be firstly presented and then applied to model the entire coil structure. An experimental prototype has been built and evaluated on a test bed under lateral and angular misalignments. Experimental results are found to be in close agreement with the theoretical predictions.