Abstract：Microwave wireless power transmission (MWPT) utilizes microwave radiation to realize long-distance wireless power transmission, a subversive power transmission technology with potentially broad application prospects. The receiving end includes a large-scale receiving array antenna, rectifier module, and power synthesis. At present, the research on receiving antenna and rectification technology has made some progress, but the research on power synthesis is inadequate. There are two main ways of power synthesis: DC and RF. Due to the inherent characteristics of microwave long-distance transmission, the radiated power distributed on the large-scale receiving array antenna needs to be uniform. Suppose one single power synthesis method is used. In that case, inappropriate rectifier input causes issues such as the rectifier working incorrectly, the rectification efficiency being low, and the load being mismatched, which seriously affects the transmission efficiency of the energy transfer system. This paper proposes a new hybrid power synthesis method with the genetic optimization algorithm. Firstly, the input-output characteristics of the rectifier with Schottky diode are analyzed. The input power-conversion efficiency characteristic curve of the rectifier is derived, and the optimal input power corresponding to the optimal conversion efficiency, i.e., the target power for RF synthesis, is determined. Next, chromosome coding rules are proposed to interconnect receiving antenna units. A power synthesis correlation matrix and uniformity evaluation indices are established. According to the target power, the receiving antenna units are dynamically grouped and synthesized with RF, which ensures microwave power homogenization across each group post-RF synthesis. Furthermore, coding rules for the rectifier circuit interconnection are devised. The rectifiers are dynamically optimized for series-parallel connection with the goal of load matching, thus achieving optimal conversion efficiency post-DC synthesis. A MWPT simulation system is constructed. A 10×10 array of receiving antenna arrays is utilized, with a total RF power input of 166.7 mW. Four channels of RF power output are obtained with a uniformity evaluation index (εr) of 1.804 using the grouped RF synthesis uniformization method. In contrast, direct RF synthesis with 100 channels yields an εr of 126.7. Following optimization through load-matching DC synthesis, an energy conversion efficiency of 91.37% is achieved, while the pure series and pure parallel DC synthesis methods are 58.89% and 22.81%, respectively. The proposed hybrid power synthesis optimization method can significantly enhance the transmission efficiency of long-distance MWPT systems.
[1] 杨奕, 张葛, 曹桂梅, 等. 基于多线圈阵列的单管无线电能传输电路优化[J]. 电工技术学报, 2023, 38(20): 5398-5410. Yang Yi, Zhang Ge, Cao Guimei, et al.Optimization on single-switch wireless power transfer circuit based on multi-coils array[J]. Transactions of China Electrotechnical Society, 2023, 38(20): 5398-5410. [2] 苏玉刚, 邓晨琳, 胡宏晟, 等. 基于电场耦合的电能信号并行传输系统串扰抑制方法[J]. 电工技术学报, 2024, 39(6): 1613-1626. Su Yugang, Deng Chenlin, Hu Hongsheng, et al.Crosstalk suppression method for electric-field coupled power and signal parallel transmission system[J]. Transactions of China Electrotechnical Society, 2024, 39(6): 1613-1626. [3] 张鹏飞, 龚立娇, 马欣欣, 等. 具有可变增益恒压特性的双线圈无线电能传输系统补偿网络设计与分析[J]. 电工技术学报, 2024, 39(5): 1256-1269, 1283. Zhang Pengfei, Gong Lijiao, Ma Xinxin, et al.Design and analysis of compensation network for dual-coil wireless power transmission system with variable gain and constant voltage characteristics[J]. Transa- ctions of China Electrotechnical Society, 2024, 39(5): 1256-1269, 1283. [4] 苏玉刚, 钱林俊, 刘哲, 等. 水下具有旋转耦合机构的电场耦合无线电能传输系统及参数优化方法[J]. 电工技术学报, 2022, 37(10): 2399-2410. Su Yugang, Qian Linjun, Liu Zhe, et al.Underwater electric-filed coupled wireless power transfer system with rotary coupler and parameter optimization method[J]. Transactions of China Electrotechnical Society, 2022, 37(10): 2399-2410. [5] 薛明, 杨庆新, 章鹏程, 等. 无线电能传输技术应用研究现状与关键问题[J]. 电工技术学报, 2021, 36(8): 1547-1568. Xue Ming, Yang Qingxin, Zhang Pengcheng, et al.Application status and key issues of wireless power transmission technology[J]. Transactions of China Electrotechnical Society, 2021, 36(8): 1547-1568. [6] 谢文燕, 陈为. 全方向无线电能传输技术研究进展[J]. 电力系统自动化, 2020, 44(4): 202-215. Xie Wenyan, Chen Wei.Research progress of omnidirectional wireless power transfer technology[J]. Automation of Electric Power Systems, 2020, 44(4): 202-215. [7] 荣灿灿, 严俐慧, 路聪慧, 等. 基于超材料与超表面的无线电能传输技术研究现状与进展综述[J]. 电工技术学报, 2023, 38(20): 5369-5384. Rong Cancan, Yan Lihui, Lu Conghui, et al.Overview on research status and progress of wireless power transfer technology based on metamaterials and metasurfaces[J]. Transactions of China Electro- technical Society, 2023, 38(20): 5369-5384. [8] 程时杰, 陈小良, 王军华, 等. 无线输电关键技术及其应用[J]. 电工技术学报, 2015, 30(19): 68-84. Cheng Shijie, Chen Xiaoliang, Wang Junhua, et al.Key technologies and applications of wireless power transmission[J]. Transactions of China Electro- technical Society, 2015, 30(19): 68-84. [9] 范兴明, 莫小勇, 张鑫. 无线电能传输技术的研究现状与应用[J]. 中国电机工程学报, 2015, 35(10): 2584-2600. Fan Xingming, Mo Xiaoyong, Zhang Xin.Research status and application of wireless power transmission technology[J]. Proceedings of the CSEE, 2015, 35(10): 2584-2600. [10] 朱博文, 王薪, 刘冰, 等. 面向空间太阳能电站应用的超大规模天线阵列模块尺寸与姿态偏差效应分析[J]. 空间电子技术, 2023, 20(3): 13-18. Zhu Bowen, Wang Xin, Liu Bing, et al.Analysis of size and attitude deviation effect of very large scale antenna array module for space solar power station application[J]. Space Electronic Technology, 2023, 20(3): 13-18. [11] Gao Jing, Jin Ke, Zhou Weiyang, et al.Subarray arrangement method based on orthogonal radiation algorithm for microwave wireless power trans- mission[C]//2023 IEEE Energy Conversion Congress and Exposition (ECCE), Nashville, TN, USA, 2023: 6161-6164. [12] Olgun U, Chen C C, Volakis J L. Investigation of rectenna array configurations for enhanced RF power harvesting[J]. IEEE Antennas and Wireless Pro- pagation Letters, 1826, 10: 262-265. [13] Lee Dongjin, Lee S J, Hwang I J, et al.Hybrid power combining rectenna array for wide incident angle coverage in RF energy transfer[J]. IEEE Transactions on Microwave Theory and Techniques, 2017, 65(9): 3409-3418. [14] 赵争鸣, 王旭东. 电磁能量收集技术现状及发展趋势[J]. 电工技术学报, 2015, 30(13): 1-11. Zhao Zhengming, Wang Xudong.The state-of-the-art and the future trends of electromagnetic energy harvesting[J]. Transactions of China Electrotechnical Society, 2015, 30(13): 1-11. [15] 曾凡剑, 孙列鹏, 施龙波, 等. 增益和相位一致性对功率合成效率的影响[J]. 强激光与粒子束, 2019, 31(5): 10-13. Zeng Fanjian, Sun Liepeng, Shi Longbo, et al.Impact of gain and phase consistency on the efficiency of power synthesis[J]. High Power Laser and Particle Beams, 2019, 31(5): 10-13. [16] Guo Lei, Zhu He, Abbosh A.Phase reconfigurable microwave power divider[J]. IEEE Transactions on Circuits and Systems II: Express Briefs, 2019, 66(1): 21-25. [17] Lu Xiao, Wang Ping, Niyato D, et al.Wireless networks with RF energy harvesting: a contemporary survey[J]. IEEE Communications Surveys & Tutorials, 2015, 17(2): 757-789. [18] Shinohara N, Matsumoto H.Experimental study of large rectenna array for microwave energy trans- mission[J]. IEEE Transactions on Microwave Theory and Techniques, 1998, 46(3): 261-268. [19] 王业清, 杨雪霞, 江超. 整流天线组阵等效模型分析与实验[J]. 上海大学学报(自然科学版), 2013, 19(3): 266-270, 285. Wang Yeqing, Yang Xuexia, Jiang Chao.Equivalent models and experiments of rectenna arrays[J]. Journal of Shanghai University (Natural Science Edition), 2013, 19(3): 266-270, 285. [20] Sakamoto T, Ushijima Y, Nishiyama E, et al.5.8-GHz series/parallel connected rectenna array using expandable differential rectenna units[J]. IEEE Transactions on Antennas and Propagation, 2013, 61(9): 4872-4875. [21] 梅欢, 杨雪霞. 圆极化整流天线阵列设计与实验[J]. 电工技术学报, 2015, 30(增刊1): 282-285. Mei Huan, Yang Xuexia.Design and experiment of circularly polarized rectifier antenna array[J]. Transactions of China Electrotechnical Society, 2015, 30(S1): 282-285. [22] Ou Junhui, Zheng Shaoyong, Andrenko A S, et al.Novel time-domain Schottky diode modeling for microwave rectifier designs[J]. IEEE Transactions on Circuits and Systems I: Regular Papers, 2018, 65(4): 1234-1244. [23] Liu Weifeng, Wang Yueyu, Song Jianjun.Research on Schottky diode with high rectification efficiency for relatively weak energy wireless harvesting[J]. Superlattices and Microstructures, 2021, 150: 106639. [24] 张彪, 刘长军. 一种高效的2.45 GHz二极管阵列微波整流电路[J]. 强激光与粒子束, 2011, 23(9): 2443-2446. Zhang Biao, Liu Changjun.A high efficiency 2.45 GHz microwave rectifier based on diode array[J]. High Power Laser and Particle Beams, 2011, 23(9): 2443-2446. [25] Lu Ping, Song Chaoyun, Huang Kama.A compact rectenna design with wide input power range for wireless power transfer[J]. IEEE Transactions on Power Electronics, 2020, 35(7): 6705-6710. [26] Mohan A, Mondal S.An impedance matching strategy for micro-scale RF energy harvesting systems[J]. IEEE Transactions on Circuits and Systems II: Express Briefs, 2021, 68(4): 1458-1462. [27] Takeshita S.Realization of optimum aperture illumination by Gaussian taper in small Fresnel number[J]. IEEE Transactions on Antennas and Propagation, 1968, 16(1): 129-130. [28] Katoch S, Chauhan S S, Kumar V.A review on genetic algorithm: past, present, and future[J]. Multimedia Tools and Applications, 2021, 80(5): 8091-8126. [29] 葛继科, 邱玉辉, 吴春明, 等. 遗传算法研究综述[J]. 计算机应用研究, 2008, 25(10): 2911-2916. Ge Jike, Qiu Yuhui, Wu Chunming, et al.Summary of genetic algorithms research[J]. Application Research of Computers, 2008, 25(10): 2911-2916.
2025, Vol. 40 
