Skip to main content

Impedance matching approach of L-section circuit with ohmic loss in reactive components

  • Satoshi Suzuki (a1), Qiaowei Yuan (a2) and Qiang Chen (a1)

Impedance matching is very important to improve transmission efficiency not only for wireless communication but also for wireless power transfer. Lumped reactive elements are usually used in the impedance matching circuit. These reactive components such as inductors and capacitors have ohmic loss. An exact approach to design the lumped matching circuit at the presence of the ohmic loss is derived in this paper. Moreover, the condition for selection of impedance matching topology is deduced not only for lossless case but also for lossy case. Finally, the effect of the ohmic loss in the impedance matching circuit on the transmission efficiency is demonstrated quantitatively.

Corresponding author
Corresponding author: S. Suzuki Email:
Hide All
[1] Simon, O.; Mahlein, J.; Turki, F.; Dörflinger, D.; Hoppe, A.: Field test results of interoperable electric vehicle wireless power transfer, in 2016 18th European Conf. on Power Electronics and Applications (EPE'16 ECCE Europe), Karlsruhe, 2016, 110.
[2] Kracek, J.; Svanda, M.; Mazanek, M.; Machac, J.: Semi-active 866 MHz RFID implantable tag fed by 6.78 MHz inductive wireless power transfer, in 2016 46th European Microwave Conf. (EuMC), London, 2016, 620622.
[3] Yuan, Q.; Chen, Q.; Sawaya, K.: Numerical analysis on transmission efficiency of evanescent resonant coupling wireless power transfer system. IEEE Trans. Antennas Propag., 58 (5) (2010), 17511758.
[4] Chen, Q.; Ozawa, K.; Yuan, Q.; Sawaya, K.: Antenna characterization for wireless power-transmission system using near-field coupling. IEEE Antennas Propag. Mag., 54 (4) (2012), 108116.
[5] Rahola, J.: Power waves and conjugate matching. IEEE Trans Circuits Syst II Express Briefs, 55 (1) (2008), 9296.
[6] Rollett, J.M.: Stability and power gain invariants of linear two ports. IRE Trans. Circuit Theory, 9 (1962), 2932.
[7] Inagaki, N.: Theory of image impedance matching for inductively coupled power transfer systems. IEEE Trans. Microw. Theory Tech., 62 (4) (2014), 901908.
[8] Roberts, S.: Conjugate-image impedances. Proc. IRE, 34 (4) (1946), 198204.
[9] 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.
[10] Yuan, Q.; Niizeki, R.: Calculator of WPT Efficiency between Transmitting and Receiving elements,” in (invited) 2017 The Applied Computational Electrimagnetics Soiety (ACES), August 2017.
[11] Moon, J.; Hwang, H.; Jo, B.; Kwon, C.K.; Kim, T.G.; Kim, S.W.: Design and implementation of a high-efficiency 6.78 MHz resonant wireless power transfer system with a 5W fully integrated power receiver. IET Power Electron., 10 (5) (2017), 577587.
[12] Shinki, Y.; Shibata, K.; Mansour, M.; Kanaya, H.: High-efficiency energy harvesting circuit with impedance matched antenna, in 2016 IEEE 18th Electronics Packaging Technology Conf. (EPTC), Singapore, 2016, 532535.
[13] Kim, J.; Kim, D.H.; Park, Y.J.: Analysis of capacitive impedance matching networks for simultaneous wireless power. Transf. Multiple Devices, 62 (5) (2015), 28072813.
[14] Suzuki, S.; Abe, S.; Yuan, Q.: Efficiency of rectify circuit with matching circuit for wireless power transfer. IEICE Tech. Rep., 114 (246) (2014), 1114, WPT2014-37.
[15] Rahola, J.: Optimization of matching circuits for antennas, in Proc. of the 5th European Conf. on Antennas and Propagation (EUCAP), Rome, 2011, 776778.
[16] Pozar, D.M.: Microwave Engineering, 4th ed. Wiley International Edition, 2011.
[17] Yuan, Q.: Effect of loss of matching circuit on efficiency of wireless power transfer system. IEICE Tech. Rep., 114 (375) (2014), 3134, WPT2014-69.
[18] Chen, Q.; Yuan, Q.: Antennas in wireless charging systems, in Handbook of Antenna Technologies, 2015, 124.
[19] Yuan, Q.; Suzuki, S.: Exact matching approach with circuit element ohmic loss, in 2016 International Symp. on Antennas and Propagation (ISAP), October 2016, 342343.
[20] Collin, R.E.: Foundations for Microwave Engineering, 2nd ed., Wiley-Interscience, Singapore, 2001.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Wireless Power Transfer
  • ISSN: -
  • EISSN: 2052-8418
  • URL: /core/journals/wireless-power-transfer
Please enter your name
Please enter a valid email address
Who would you like to send this to? *



Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed