New Design Method of Wireless Power Transfer System Using Loop Antennas

루프 안테나를 이용한 무선 전력 전송 시스템의 새로운 설계법

  • Kim, Hee-Seung (Department of Electronics Engineering, Kookmin University) ;
  • Won, Do-Hyun (Department of Electronics Engineering, Kookmin University) ;
  • Lim, Jae-Bong (Department of Electronics Engineering, Kookmin University) ;
  • Jang, Byung-Jun (Department of Electronics Engineering, Kookmin University)
  • 김희승 (국민대학교 전자공학부) ;
  • 원도현 (국민대학교 전자공학부) ;
  • 임재봉 (국민대학교 전자공학부) ;
  • 장병준 (국민대학교 전자공학부)
  • Published : 2010.01.31


In this paper, we propose a new design method to design a wireless power transfer system using loop antennas for consumer electronics. This method can simply design a wireless power transfer system only using measurements of coupling coefficients and simple equations of equivalent circuit model about loop antennas without complicated electromagnetic analysis. Using the proposed design method, a wireless power transfer system with a pair of loop antennas operating at the frequency of 13.56 MHz, which have a dimension of $50{\times}50\;cm^2$, is designed and implemented. The input return loss, coupling coefficient, efficiency, and input impedance variation with respect to a distance between loop antennas were measured. The proposed design method provides good agreements between measured and predicted results. Also, the wireless power transfer system with impedance matching circuits designed by the proposed design method shows two times higher efficiency characteristics than the case with the general $50\;{\Omega}$ impedance matching circuits. Therefore, we verified that our design method could be an effective tool to design a wireless power transfer system.


Wireless Power Transmission;Loop Antenna;Coupling Coefficient;Impedance Matching;Efficiency;Resonance


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