Lateral and Angular Misalignments Analysis of a New PCB Circular Spiral Resonant Wireless Charger

Detailed theoretical and numerical analysis reveals that the resonant wireless power transmission (R-WPT) technology, which was first reported by a research team at the Massachusetts Institute of Technology, is efficient and practical for mid-range wireless energy exchange to transmit nontrivial amount of power wirelessly over a long distance. This paper presents an analytical model, based on that technology, for resonant magnetic coupling to incorporate misalignments between the transmitter and receiver of this advanced system. The relationships among the energy transfer efficiency and several key parameters of the system are analyzed using finite element method (FEM). Study is done for the magnetic field of the receiver coil when it is laterally and angularly misaligned from the transmitter. A resonant near-field power transfer method is suggested to incorporate coil characteristics and misalignments. Experiments have also been carried out to facilitate quantitative comparison. It is shown that a maximum degree of misalignment can be defined in a given application. The analysis reported allows a formal design procedure to be established for the optimization of resonant wireless power transmission for a given application.