This paper presents the design of a compact-integrated reconfigurable rectenna array containing 2x2 compact microstrip patch antennas based on a fractal model with the rectifier circuit integrated into the same physical structure and usable in practical conditions. In this array configuration, four rectennas were mounted in a planar structure with total dimensions of 85x85 mm using FR-4 dielectric and with recongurable DC output that was tested in three ways: series-association, parallel-association and series-parallel association. In the series-association the rectenna array was able to generate the DC power that reached 6.51 V and maximum efficiency of 64.5%; in the parallel-association it generated the DC power that reached 1.58 V and maximum efficiency of 65.3%; in series-parallel-association it generated the DC power that reached 3.00 V and maximum efficiency of 64.5%. The results showed that rectennas in array configuration are feasible to be used as power supplies to electronic devices in real situations.
2. Khemar, A., A. Kacha, H. Takhedmit, and G. Abib, "Design and experiments of a dual-band rectenna for ambient RF energy harvesting in urban environments," IET Microwaves, Antennas & Propagation, Vol. 12, No. 1, 49-55, 2018.
3. Lu, P., X.-S. Yang, and B.-Z. Wang, "A two-channel frequency reconfigurable rectenna for microwave power transmission and data communication," IEEE Transactions on Antennas and Propagation, Vol. 65, No. 12, 2017.
4. Lee, D.-J., S.-J. Lee, I.-J. Hwang, W.-S. Lee, and J.-W. Yu, "Hybrid power combining rectenna array for wide incident angle coverage in RF energy transfer," IEEE Transactions on Microwave Theory and Techniques, Vol. 65, No. 9, 2017.
5. Carvalho, N. B., et al., "Critical review on smart clothing product development," IEEE Transactions on Microwave Theory and Techniques, Vol. 62, No. 4, 2014.
6. Hamani, A., et al., "Design of rectenna series-association circuits for radio frequency energy harvesting in CMOS FD-SOI 28 nm," IET Circuits, Devices & Systems, Vol. 12, No. 1, 40-49, 2018.
7. Chuma, E. L., L. de la T. Rodrguez, Y. Iano, L. L. Bravo Roger, and M. A. Sanchez-Soriano, "Compact rectenna based on a fractal geometry with a high conversion energy efficiency per area," IET Microwaves, Antennas & Propagation, Vol. 12, No. 2, 173-178, 2018.
8. Ladan, S., N. Ghassemi, A. Ghiotto, and K. Wu, "Highly efficient compact rectenna for wireless energy harvesting application," IEEE Microwave Magazine, 117-122, 2013.
9. Valenta, C. R. and G. D. Durgin, "Harvesting wireless power: survey of energy-harvester conversion efficiency in far-field wireless power transfer systems," IEEE Microwave Magazine, 108-120, 2014.
10. Olgun, U., C.-C. Chen, and J. L. Volakis, "Investigation of rectenna array configurations for enhanced RF power harvesting," IEEE Antennas and Wireless Propagation Letters, Vol. 10, 262-265, 2011.
11. Hagerty, A., F. B. Helmbrecht, W. H. McCalpin, R. Zane, and Z. B. Popovic, "Recycling ambient microwave energy with broad-band rectenna arrays," IEEE Transactions on Microwave Theory and Techniques, Vol. 52, No. 3, 2004.
12. Zbitou, J., M. Latrach, and S. Toutain, "Hybrid rectenna and monolithic integrated zero-bias microwave rectifier," IEEE Transactions on Microwave Theory and Techniques, Vol. 54, No. 1, 2006.
13. Gianvittorio, J. P. and Y. Rahmat-Samii, "Fractal antennas: A novel antenna miniaturization technique, and applications," IEEE Antennas and Propagation Magazine, Vol. 44, 20-36, 2002.
14. Falkenstein, E., M. Roberg, and Z. Popovic, "Low-power wireless power delivery," IEEE Transactions on Microwave Theory and Techniques, Vol. 60, No. 7, 2012.
15. Pozar, D. M., "Input impedance and mutual coupling of rectangular microstrip antennas," IEEE Transactions on Antennas and Propagation, Vol. 30, No. 6, 1982.