Analytical design study of a novel witricity charger with lateral and angular misalignments for efficient wireless energy transmission

Junhua Wang, Siu Lau Ho, Weinong Fu, Mingui Sun

Research output: Journal article publicationJournal articleAcademic researchpeer-review

57 Citations (Scopus)


Detailed theoretical and numerical analysis reveals that Witricity, 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 Witricity technology, for resonant magnetic coupling to address 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). Formulae are derived for the magnetic field of the receiver coil when it is laterally and angularly misaligned from the transmitter. A resonant near-field power transfer formula is suggested to incorporate the 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 Witricity for a given application.
Original languageEnglish
Article number6028191
Pages (from-to)2616-2619
Number of pages4
JournalIEEE Transactions on Magnetics
Issue number10
Publication statusPublished - 1 Oct 2011


  • Angular misalignment
  • lateral misalignment
  • magnetic coupling
  • Witricity

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Electronic, Optical and Magnetic Materials

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