Author details

minimum variation of PTEs is preserved as depicted in Figure 11. Positioned at perfect alignment, PTE for each frequency is 90.11 and 80.56% at 6.78 and

8. Conclusions

Recent Wireless Power Transfer Technologies

discretion.

62

Acknowledgements

Conflict of interest

13.56 MHz, respectively. Variation of PTEs at 9.55% is satisfactory considering ratio between frequencies is significantly small at only two for single-coil approach.

Constraints of dual-band near-field wireless energy transfer links are presented. Front-end mitigation techniques in sustaining acceptable performance metrics for dual-band WET system are reviewed. Accomplishment of satisfactory transfer efficiency at a relevant axial distance regardless of resonance frequencies preferred is imperative besides having resilience against coupling variations and displacement offset from ideal orientation. Deciding on the design approaches conveyed above is narrowed down to either meeting specifications of transfer efficiency proportionality between selected frequencies or sufficient energy and data transfer capability. As such, precautionary steps should be undertaken in determining technique adoption in an effort to strike a balance between performance goals, design complexity, and physical and budgetary restraints. All the aforementioned techniques discussed in this chapter serve as a benchmark or recommended framework for designers'

This work is jointly supported by CREST under Grant 4B151 and the Institute of

Thanks to Kristina Tijan for invitation to contribute this chapter to the book

Electronics and Telecommunication of Rennes (IETR).

The authors declare no conflict of interest.

Notes/Thanks/Other declarations

Appendixes and nomenclature

"Wireless Energy Transfer Technology".

Symbol Parameter f1,2 frequency 1, 2 k coupling coefficient ar planar displacement

ax horizontal lateral displacement ay vertical lateral displacement θ angular displacement z transfer distance

Lai Ly Pon1 , Mohamed Himdi<sup>2</sup> \*, Sharul Kamal Abdul Rahim<sup>1</sup> and Chee Yen Leow<sup>1</sup>

1 Wireless Communication Center, School of Electrical Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, Johor Bahru, Malaysia

2 Institute of Electronics and Telecommunication of Rennes, University of Rennes 1, Rennes, France

\*Address all correspondence to: mohamed.himdi@univ-rennes1.fr

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
