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Gain expressions for resonant inductive wireless power transfer links with one relay element

  • Franco Mastri (a1), Mauro Mongiardo (a2), Giuseppina Monti (a3), Marco Dionigi (a2) and Luciano Tarricone (a3)...

In this paper, a resonant inductive wireless power transfer link using a relay element is analyzed. Different problems of practical interest are considered and solved by modeling the link as a lossy two-port network. According to the two-port network formalism, the standard gain definition (i.e. the power, the available, and the transducer gains) are used for describing the network behavior. Firstly, the case of a link with given parameters is considered and the analytical expressions of the optimal terminating impedances for maximizing the link gains are derived. Later on, the case of a link with given source and load is analyzed and the possibility of maximizing the performance by acting either on the transmitting or on the receiving side is investigated. It is shown that by using a single relay element, it is not always possible to maximize all the figures of merit that could be of interest in the WPT context. Theoretical data are validated by comparisons with circuital simulation results.

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Corresponding author: G. Monti Email:
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[1] Costanzo, A.; et al. Electromagnetic energy harvesting and wireless power transmission: a unified approach. Proc. IEEE, 102 (11) (2014), 16921711.
[2] Bird, T.S.; Rypkema, N.; Smart, K.W.: Antenna impedance matching for maximum power transfer in wireless sensor networks, in IEEE Sensors, Amsterdam, Netherlands, 25–28 Oct. 2009, 916919.
[3] Imura, T.; Okabe, H.; Hori, Y.: Basic experimental study on helical antennas of wireless power transfer for electric vehicles by using magnetic resonant couplings, in Proc. of Vehicle Power and Propulsion Conference, Dearborn, MI, USA, 7–10 Sept. 2009, 936–940.
[4] Monti, G.; Arcuti, P.; Tarricone, L.: Resonant inductive link for remote powering of pacemakers. IEEE Trans. Microw. Theory Tech., 63 (11) (2015), 38143822.
[5] Monti, G.; Dionigi, M.; Mongiardo, M.; Perfetti, R.: Optimal design of wireless energy transfer to multiple receivers: power maximization. IEEE Trans. Microw. Theory Tech., 65 (1) (2017), 260269.
[6] Del Prete, M.; Costanzo, A.; Georgiadis, A.; Collado, A.; Masotti, D.; Popovic, Z.: Energy-autonomous Bi-directional Wireless Power Transmission (WPT) and energy harvesting circuit, in IEEE MTT-S Int. Microwave Symp. (IMS), Phoenix, AZ, USA, 2015, 14.
[7] Li, S.; Mi, C.C.: Wireless power transfer for electric vehicle applications. IEEE J. Emerging Sel. Top. Power Electron., 3 (1) (2015), 417.
[8] Karalis, A.; Joannopoulos, J.D.; Soljačić, M.: Efficient wireless non-radiative mid-range energy transfer. Ann. Phys., 323 (1) (2008), 3448.
[9] Monti, G.; et al. Wireless power transfer between one transmitter and two receivers: optimal analytical solution. Wireless Power Transf., 3 (2016), 6373.
[10] Dionigi, M.; Mongiardo, M.; Perfetti, R.: Rigorous network and full-wave electromagnetic modeling of wireless power transfer links. IEEE Trans. Microw. Theory Tech., 63 (1) (2015), 6575.
[11] Aditya, K.; Williamson, S.S.: A review of optimal conditions for achieving maximum power output and maximum efficiency for a series–series resonant inductive link. IEEE Trans. Transp. Electrification, 3 (2) (2017), 303311.
[12] Mirbozorgi, S.A.; Yeon, P.; Ghovanloo, M.: Robust wireless power transmission to mm-sized free-floating distributed implants. IEEE Trans. Biomed. Circuits Syst., 11 (3) (2017), 692702.
[13] Monti, G.; Costanzo, A.; Mastri, F.; Mongiardo, M.; Tarricone, L.: Rigorous design of matched wireless power transfer links based on inductive coupling. Radio Sci., 51 (6) (2016), 858867.
[14] Zhang, F.; Hackworth, S.A.; Fu, W.; Li, C.; Mao, Z.; Sun, M.: Relay effect of wireless power transfer using strongly coupled magnetic resonances. IEEE Trans. Magn., 47 (5) (2011), 14781481.
[15] Hui, S.Y.R.; Zhong, W.; Lee, C.K.: A critical review of recent progress in mid-range wireless power transfer. IEEE Trans. Power Electron., 29 (9) (2014), 45004511.
[16] Monti, G., Tarricone, L., Dionigi, M.; Mongiardo, M.: Magnetically coupled resonant wireless power transmission: An artificial transmission line approach, in Proc. of the Microwave Conf. (EuMC), Amsterdam, Netherlands, Oct. 2012, 233236.
[17] Monti, G.; Corchia, L.; Tarricone, L.; Mongiardo, M.: A network approach for wireless resonant energy links using relay resonators. IEEE Trans. Microw. Theory Tech., 64 (10) (2016), 32713279.
[18] Luo, B.; Wu, S.; Zhou, N.: Flexible design method for multi-repeater wireless power transfer system based on coupled resonator bandpass filter model. IEEE Trans. Circuits Syst. I Regul. Pap., 61 (11) (2014), 933942.
[19] Ahn, D.; Hong, S.: A study on magnetic field repeater in wireless power transfer. IEEE Trans. Ind. Electron., 60 (1) (2013), 360371.
[20] Sun, T.; Xie, X.; Li, G.; Gu, Y.; Deng, Y.; Wang, Z.: System with an efficiency-enhanced power receiver for motion-free capsule endoscopy inspection. IEEE Trans. Biomed Eng., 59 (11) (2012), 32473253.
[21] Zhong, W.; Lee, C.K.; Hui, S.Y.R.: General analysis on the use of Tesla's resonators in domino forms for wireless power transfer. IEEE Trans. Ind. Electron., 60 (1) (2013), 261270.
[22] Kurs, A.; Karalis, A.; Moffatt, R.; Joannopoulos, J.D.; Fisher, P.; Soljacic, M.: Wireless power transfer via strongly coupled magnetic resonances. Science, 317 (5834) (2007), 83.
[23] Lee, G.; Waters, B.H.; Shi, C.; Park, W.S.; Smith, J.R.: Design considerations for asymmetric magnetically coupled resonators used in wireless power transfer applications, in IEEE Topical Conf. on Biomedical Wireless Technologies, Networks, and Sensing Systems (BioWireleSS), Austin, TX, USA, 2013, 13.
[24] Kim, J.; Son, H.-C.; Kim, K.-H.; Park, Y.-J.: Efficiency analysis of magnetic resonance wireless power transfer with intermediate resonant coil. IEEE Antennas Wireless Propag. Lett., 10 (2011), 389392.
[25] Lee, B.; Kiani, M.; Ghovanloo, M.: A triple-loop inductive power transmission system for biomedical applications. IEEE Trans. Biomed. Circuits Syst., 10 (1) (2016), 138148.
[26] Zhong, W.; Zhang, C.; Liu, X.; Hui, S.: A methodology for making a three-coil wireless power transfer system more energy efficient than a two-coil counterpart for extended transfer distance. IEEE Trans. Power Electron., 30 (2) (2015), 32883297.
[27] Kiani, M.; Jow, U.-M.; Ghovanloo, M.: Design and optimization of a 3-coil inductive link for efficient wireless power transmission. IEEE Trans. Biomed. Circuits Syst., 5 (6) (2011), 579591.
[28] Shimada, A.; Ito, Y.; Uehara, H.; Ohira, T.: Effect of hop counts on power division ratio in multi-hop power transfer via magnetic resonance, in IEEE Wireless Power Transfer Conf., Perugia, Italy, 2013, 179184.
[29] Monti, G.; Costanzo, A.; Mastri, F.; Mongiardo, M.: Optimal design of a wireless power transfer link using parallel and series resonators. Wireless Power Transf., 3 (2) (2016), 105116.
[30] Roberts, S.: Conjugate-Image Impedances. Proc. of the IRE, 34 (4) (1946), 198204.
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Wireless Power Transfer
  • ISSN: -
  • EISSN: 2052-8418
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