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By Y. Zhang and T. Yoshikawa

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Angular misalignment is an issue for many potential applications of wireless power transfer (WPT). It is necessary to keep coupling coefficient, especially the magnetic coupling to be insensitive to angular misalignment. This paper analyzes the coupling between the spiral resonators when one resonator rotates with respect to the other. The quantitative data of magnetic and electric coupling components as well as the total coupling coefficient in angular misalignments are presented. Furthermore, a 3D spiral resonator which is less sensitive to angular misalignment is proposed. The coupling when the 3D spiral rotates is studied and the results of analysis and experiment both show that the proposed 3D spiral resonator can keep coupling coefficient at a certain level under angular misalignment.

Y. Zhang and T. Yoshikawa, "Magnetic and Electric Coupling Analysis for Angular Misalignment of Spiral Resonators in WPT Systems," Progress In Electromagnetics Research M, Vol. 76, 1-8, 2018.

1. Tesla, N., "Transmission of electrical energy without wire," Elect. World Eng., Mar. 5, 1904, Online Available: ww.tfcbooks.com/tesla/.

2. Kurs, A., A. Karalis, R. Moffatt, J. D. Joannopoulos, P. Fisher, and M. Soljacic, "Wireless power transfer via strongly coupled magnetic resonances," Science, Vol. 317, 83-86, Jul. 2007.

3. Shonohara, N., Wireless Power Transfer via Radiowaves, ISTE Ltd. and John Wiley & Sons, Inc., 2014.

4. Awai, I., "Magnetic resonant wireless power transfer," Nikkei Electronics, 2011 (in Japanese).

5. Ohira, T., "Maximum available efficiency formulation based on a black-box model of linear two port power transfer systems," IEICE Electronics Express, ELEX, Vol. 11, No. 13, 1-6, #20140448, Jun. 2014.

6. Zhang, J., X. Yuan, C. Wang, and Y. He, "Comparative analysis of two-coil and three-coil structures for wireless power transfer," IEEE Transactions on Power Electronics, Vol. 32, No. 1, 341-352, 2017.

7. Tierney, B. B. and A. Grbic, "Design of self-matched planar loop resonators for wireless nonradiative power transfer," IEEE Transactions on Microwave Theory and Techniques, Vol. 62, No. 4, 909-919, 2014.

8. Hui, S. Y. R., W. Zhong, and C. K. Lee, "A critical review of recent progress in mid-range wireless power transfer," IEEE Transactions on Power Electronics, Vol. 29, No. 9, 4500-4511, 2014.

9. Fernandes, R. D., J. N. Matos, and N. B. Carvalho, "Resonant electrical coupling: Circuit model and first experimental results," IEEE Transactions on Microwave Theory and Techniques, Vol. 63, No. 9, 2983-2990, 2015.

10. Zhang, X. Y., C. D. Xue, and J. K. Lin, "Distance-insensitive wireless power transfer using mixed electric and magnetic coupling for frequency splitting suppression," IEEE Transactions on Microwave Theory and Techniques, Vol. 65, No. 11, 4307-4316, 2017.

11. Hong, J.-S., "Couplings of asynchronously tuned coupled microwave resonators," IEE Proceedings - Microwaves, Antennas and Propagation, Vol. 147, No. 5, 354-358, 2000.

12. Hong, J.-S. and M. J. Lancaster, Microstrip Filters for RF/Microwave Applications, John Wiley & Sons, Inc., 2001.

13. Awai, I., "New expressions for coupling coefficient between resonators," IEICE Trans. Electron., E88C, Vol. 12, 2295-2301, Dec. 2005.

14. Awai, I., S. Iwamujra, H. Kubo, and A. Sanada, "Separation of coupling coefficient between resonators into electric and magnetic contributions," IEICE, Vol. J88-C, No. 12, 1033-1039, 2005 (in Japanese).

15. Elnaggar, S. Y., R. J. Tervo, and S. M. Mattar, "Coupled mode theory applied to resonators in the presence of conductors," IEEE Transactions on Microwave Theory and Techniques, Vol. 63, No. 7, 2124-2132, 2015.

16. Awai, I. and Y. Zhang, "Coupling coefficient of resonators," IEICE Trans. Electron, Vol. J89-C, No. 12, 962-968, 2006 (in Japanese).

17. Awai, I. and Y. Zhang, "Phenomenological and essentialismic theories of coupling between the resonators," IEICE Trans. Electron, Vol. J98-C, No. 12, 314-321, 2015 (in Japanese).

18. Awai, I., Y. Zhang, T. Komori, and T. Ishizaki, "Coupling coefficient of spiral resonators used for wireless power transfer," 2010 Asia-Pacific Microwave Conference, 773-776, Yokohama, Japan, Dec. 2010.

19. Zhang, Y., T. Yoshikawa, and I. Awai, "Analysis of electric and magnetic coupling components for spiral resonators used in wireless power transfer," 2014 Asia-Pacific Microwave Conference, 1366-1368, 2014.

20. Zhang, Y., T. Yoshikawa, and T. Kitahara, "A quantitative analysis of coupling for a WPT system including dielectric/magnetic materials," Progress In Electromagnetics Research Letters, Vol. 72, 127-134, 2018.

21. Sampath, J. P. K., A. Arokiaswami, and D. M. Vilathgamuwa, "Figure of merit for the optimization of wireless power transfer system against misalignment tolerance," IEEE Transactions on Power Electronics, Vol. 32, No. 6, 4359-4369, 2017.

22. Lin, D., C. Zhang, and S. Y. Ron Hui, "Mathematic analysis of omnidirectional wireless power transfer - Part-II three-dimensional systems," IEEE Transactions on Power Electronics, Vol. 32, No. 1, 613-624, 2017.

23. Badr, B. M., R. Somogyi-Gsizmazia, K. R. Delaney, and N. Dechev, "Wireless power transfer for telemetric devices with variable orientation, for small rodent behavior monitoring," IEEE Sensors Journal, Vol. 15, No. 4, 2144-2156, 2015.

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