Printed split-ring loops with high q-factor for wireless power transmission

Jingchen Wang, Mark Paul Leach, Eng Gee Lim*, Zhao Wang, Rui Pei, Zhenzhen Jiang, Yi Huang

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)


The use of printed spiral coils (PSCs) as inductors in the construction of Wireless Power Transmission (WPT) circuits can save space and be integrated with other circuit boards. The challenges and issues of PSCs present for WPT mainly relate to maintaining an inductive characteristic at frequencies in Ultra High Frequency (UHF) band and to maximising the power transfer efficiency (PTE) between primary and secondary circuits. A new technique is proposed to increase the Q-factor relative to that offered by the PSC, which is shown to enhance WPT performance. This paper provides four-turn planar split-ring loops with high Q-factor for wireless power transmission at UHF bands. This design enhances the power transfer efficiency more than 12 times and allows for a greater transfer distance from 5 mm to 20 mm, compared with a conventional planar rectangular spiral coil.

Original languageEnglish
Article number2884
JournalElectronics (Switzerland)
Issue number22
Publication statusPublished - 1 Nov 2021


  • Magnetic resonance coupling
  • Planar spiral coil
  • Split-ring loops
  • Wireless power transmission

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