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http://dx.doi.org/10.5515/JKIEES.2010.10.4.224

Beam Efficiency of Wireless Power Transmission via Radio Waves from Short Range to Long Range  

Shinohara, Naoki (Department of Research Institute for Sustainable Humanosphere, Kyoto University)
Publication Information
Journal of electromagnetic engineering and science / v.10, no.4, 2010 , pp. 224-230 More about this Journal
Abstract
Wireless power transmission (WPT) is useful technology in near future. There are some kinds of the WPT technologies, WPT via radio waves, resonance coupling, and inductive. Especially the WPT via radio waves is used for multi-purposes from short range to long range application. However, unfortunately it is misunderstood that it is low efficiency and low power. In this paper, I show the theory of beam efficiency between transmitting antennas and receiving antennas and also show some high efficient applications of the WPT via radio waves. Especially, I pick up a wireless power charging system of an electric vehicle and show the experimental results. I show difference between the theory of beam efficiency and the experimental results of short range WPT. I indicate that reasons of poor beam efficiency in the experiment are (1) change of impedance caused by mutual coupling between transmitting antennas and receiving antennas, (2) oblique direction of microwave power to receiving antennas caused by short distance.
Keywords
Wireless Power Transmission; Microwave; Beam Efficiency; Electric Vehicle;
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1 M. Otsuka, N. Omuro, K. Kakizaki, S. Saitoh, M. Kuroda, K. Horiuchi, and T. Soejima, "Relation between spacing and receiving efficiency of finite rectenna array (in Japanese)," IEICE Trans B-II, vol. J74-B-II, no. 3, pp. 133-139, 1990.
2 N. Tesla, "The transmission of electric energy without wires," The Thirteenth Anniversary Number of the Electrical World and Engineer, Mar. 1904.
3 W. C. Brown, "The history of power transmission by radio waves," IEEE Trans. MTT, MTT-32, no. 9, pp. 1230-1242, 1984.   DOI
4 N., Shinohara, H. Matsumoto, "Wireless charging sys- tem by microwave power transmission for electric motor vehicles (in Japanese)," IEICE Trans. C, vol. J87-C, no. 5, pp. 433-443, 2004.
5 N. Shinohara, J. Kojima, T. Mitani, T. Hashimoto, N. Kishi, S. Fujita, T. Mitamura, H. Tonomura, and S. Nishikawa, "Assessment study of electric vehicle charging system with microwave power transmission II (in Japanese)," Tech. Report of IEICE, SPS2006-18, pp. 21-24, 2006.
6 W. C. Brown, "Adapting microwave techniques to help solve future energy problems," 1973 G- MTT International Microwave Symposium Digest of Technical Papers 73.1, pp. 189-191, 1973.
7 T. Miura, N. Shinohara, and H. Matsumoto, "Experimental study of microwave power transmission efficiency (in Japanese)," Tech. Report of IEICE, AP98-124, pp. 21-24, 1998.
8 US Department of Energy and NASA; Satellite Power System; Concept Development and Evaluation Program, Reference System Report, Oct. 1978 (Published Jan. 1979).
9 H. Matsumoto, "Research on solar power station and microwave power transmission in Japan: Review and perspectives," IEEE Microwave Magazine, no. 12, pp. 36-45, 2002.
10 http://www.kantei.go.jp/jp/singi/utyuu/basic_ plan.pdf
11 W. C. Brown, "Beamed microwave power transmission and its application to space," IEEE Trans. MTT, vol. 40, no. 6, pp.1239-1250, 1992.   DOI   ScienceOn
12 ITU SG1 Delayed contribution Document 1A/18-E, Update of Information in Response to Question ITU R 210/1 on Wireless Power Transmission, Oct. 2000.
13 B. L. Diamond, "A generalized approach to the analysis of infinite planar array antennas," Proc. of IEEE, vol. 56, pp. 1837-1851, 1968.   DOI   ScienceOn
14 L. Stark, "Microwave theory of phased array antenna- A review," Proc. of IEEE, vol. 62, pp. 1661-1701, 1974.   DOI   ScienceOn
15 K. Itoh, T. Ohgane, and Y. Ogawa, "Rectenna composed of a circular microstrip antenna," Space Power, vol. 6, pp. 193-198, 1986.
16 K. Itoh, T. Ohgane, and Y. Ogawa, "Absorption efficiency of rectenna composed of magnetic current antennas (in Japanses)," Tech. Report of IEICE, AP84-69, pp. 9-14, 1984.
17 http://www.kantei.go.jp/jp/singi/utyuu/keikaku/ pamph_en.pdf
18 S. Adachi, O. Suzuki, and S. Abe, "Receiving efficiency of an infinite phased array antenna above a reflecting plane (in Japanese)," IEICE Trans B, vol. J64-B, no. 6, pp. 566-567, 1981.