{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T03:04:15Z","timestamp":1760151855707,"version":"build-2065373602"},"reference-count":45,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2022,9,10]],"date-time":"2022-09-10T00:00:00Z","timestamp":1662768000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Project of National Key R&amp;D Program of China","award":["2020YFB180 7203"],"award-info":[{"award-number":["2020YFB180 7203"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>In this paper, we investigate an unmanned aerial vehicle (UAV)-assisted wireless power transfer (WPT) system, in which a set of UAV-mounted mobile energy transmitters (ETs) are dispatched to broadcast wireless energy to an energy receiver (ER) on the ground. In particular, we aim to maximize the amount of energy transferred to the ER during a finite UAV\u2019s flight period, subject to the UAV\u2019s maximum speed and collision avoidance constraints. First, the basic one\/two-UAV scenarios are researched in detail, which show that UAVs should hover at fixed locations during the whole charging period. Specifically, the Lagrange multiplier method is employed to solve the proposed optimization problem for the case of two UAV situation. Specifically, the general conclusions based on the theoretical analysis of one\/two-UAV scenarios are drawn contribute to deducing the trajectory design of UAVs when the number of UAVs increases from three to seven. The obtained trajectory solution implies that UAVs should be evenly distributed on the circumference with point (0,0,H) as the center and UAVs\u2019 safe distance as the radius. Finally, numerical results are provided to validate the trajectory design algorithm for the multiple UAVs-enabled single-user WPT system.<\/jats:p>","DOI":"10.3390\/s22186859","type":"journal-article","created":{"date-parts":[[2022,9,13]],"date-time":"2022-09-13T04:05:41Z","timestamp":1663041941000},"page":"6859","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":10,"title":["Trajectory Design for Multi-UAV-Aided Wireless Power Transfer toward Future Wireless Systems"],"prefix":"10.3390","volume":"22","author":[{"given":"Jun","family":"Mu","sequence":"first","affiliation":[{"name":"Space Star Technology Co., Ltd., Beijing 100086, China"}]},{"given":"Zhaojie","family":"Sun","sequence":"additional","affiliation":[{"name":"The Key Laboratory of Science and Technology on Communications, University of Electronic Science and Technology of China, Chengdu 611731, China"}]}],"member":"1968","published-online":{"date-parts":[[2022,9,10]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"757","DOI":"10.1109\/COMST.2014.2368999","article-title":"Wireless networks with RF energy harvesting: A contemporary survey","volume":"17","author":"Lu","year":"2014","journal-title":"IEEE Commun. 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