The microwave to direct current (MW-DC) conversion efficiency of a rectifier drops significantly in a dual-frequency microwave power transmission (MPT) system. The measured data show that the MW-DC efficiency of a rectifier drops from 67% to 53% when the microwave source is switched from a continuous wave to a dual-tone waveform at the same power level. It is mainly due to the intermodulation effects resulted from a nonlinear component, e.g., the diode, in a rectifier. A novel rectifier is designed to improve the MW-DC efficiency by recycling the intermodulation power besides the harmonic power. With the novel configuration, the maximum MW-DC conversion efficiency of 62% can be achieved for a dual-tone waveform input at 17 dBm. It implies that more than one half of the intermodulation power has been recycled to DC power.
2. Brown, W. C., "Experiments in the transportation of energy by microwave beam," IRE International Convention Record, Vol. 12, No. 2, 8-12, 1964.
doi:10.1109/IRECON.1964.1147324
3. Brown, W. C., "The history of power transmission by radio waves," IEEE Transactions on Microwave Theory and Techniques, Vol. 32, No. 9, 1230-1242, Sep. 1984.
doi:10.1109/TMTT.1984.1132833
4. Mcspadden, J. O., T. Yoo, and K. Chang, "Theoretical and experimental investigation of a rectenna element for microwave power transmission," IEEE Transactions on Microwave Theory and Techniques, Vol. 40, No. 12, 2359-2366, Dec. 1992.
doi:10.1109/22.179902
5. He, Q., K. Huang, and C. Liu, "A compact 5.8 GHz rectifying circuit design and experiments," PIERS Proceedings, 1756-1759, Beijing, China, Mar. 23-27, 2009.
6. Ren, Y.-J., M. F. Farooqui, and K. Chang, "A compact dual-frequency rectifying antenna with high-orders harmonic-rejection," IEEE Transactions on Antennas and Propagation, Vol. 55, No. 7, 2110-2113, Jul. 2007.
doi:10.1109/TAP.2007.900275
7. Wei, X. C., E. P. Li, Y. L. Guan, and Y. H. Chong, "Simulation and experimental comparison of different coupling mechanisms for the wireless electricity transfer," Journal of Electromagnetic Waves and Applications, Vol. 23, No. 7, 925-934, 2009.
doi:10.1163/156939309788355180
8. Choi, J. and C. Seo, "High-efficiency wireless energy transmission using magnetic resonance based on negative refractive index metamaterial ," Progress In Electromagnetics Research, Vol. 106, 33-47, 2010.
doi:10.2528/PIER10050609
9. Peng, L., O. Breinbjerg, and N. A. Mortensen, "Wireless energy transfer through non-resonant magnetic coupling," Journal of Electromagnetic Waves and Applications, Vol. 24, No. 11-12, 1587-1598, 2010.
doi:10.1163/156939310792149795
10. He, Q. and C. Liu, "An enhanced microwave rectifying circuit using HSMS-282," Microwave and Optical Technology Letters, , Vol. 51, No. 4, 1151-1153, 2009.
doi:10.1002/mop.24237
11. Suh, Y. and K. Chang, "A novel low-cost high-conversion-efficiency microwave power detector using GaAs FET," Microwave and Optical Technology Letters, Vol. 44, No. 1, 29-31, 2005.
doi:10.1002/mop.20537
12. Wei, X. C., E. P. Li, Y. L. Guan, and Y. H. Chong, "Simulation and experimental comparison of different coupling mechanisms for the wireless electricity transfer," Journal of Electromagnetic Waves and Applications, Vol. 23, No. 7, 925-934, 2009.
doi:10.1163/156939309788355180
13. Gao, Y.-Y., X.-X. Yang, C. Jiang, and J.-Y. Zhou, "A circularly polarized rectenna with low profile for wireless power transmission," Progress In Electromagnetics Research Letters, Vol. 13, 41-49, 2010.
doi:10.2528/PIERL09111805
14. Riviere, S., F. Alicalapa, A. Douyere, and J.-D. Lan Sun Luk, "A compact rectenna device at low power level," Progress In Electromagnetics Research C, Vol. 16, 137-146, 2010.
doi:10.2528/PIERC10071604
15. Yamaoto, T., K. Fujimori, M. Sanagi, and S. Nogi, "The mWclass high efficient RF-DC conversion circuit using the resonance structure," Proceedings of ISAP 2007, Niigata, Japan, 2007.
16. Ren, Y. J. and K. Chang, "5.8-GHz circularly polarized dual-diode rectenna and rectenna array for microwave power transmission," IEEE Transactions on Microwave Theory and Techniques, Vol. 54, No. 4, 1495-1502, Apr. 2006.
doi:10.1109/TMTT.2006.871362
17. Zhang, B., X. Zhao, C. Yu, K. Huang, and C. Liu, "A power enhanced high efficiency 2.45 GHz rectifier based on diode array," Journal of Electromagnetic Waves and Applications, Vol. 25, No. 5-6, 765-774, 2011.
doi:10.1163/156939311794827159
18. Huang, W., C. Liu, L. Yan, and K. Huang, "A miniaturized dual-band power divider with harmonic suppression for GSM applications," Journal of Electromagnetic Waves and Applications, Vol. 24, No. 1, 81-91, 2010.
doi:10.1163/156939310790322082
19. Wang, W., C. Liu, L. Yan, and K. Huang, "A novel power divider based on dual-composite right/left handed transmission line," Journal of Electromagnetic Waves and Applications, Vol. 23, No. 8-9, 1173-1180, 2009.