{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T02:08:39Z","timestamp":1760234919671,"version":"build-2065373602"},"reference-count":26,"publisher":"MDPI AG","issue":"13","license":[{"start":{"date-parts":[[2021,6,29]],"date-time":"2021-06-29T00:00:00Z","timestamp":1624924800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["SFRH\/BD\/143204\/2019","SFRH\/BD\/142403\/2018"],"award-info":[{"award-number":["SFRH\/BD\/143204\/2019","SFRH\/BD\/142403\/2018"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>The main goal of this paper is to present a three-dimensional (3D) antenna array to improve the performance of wireless power transmission (WPT) systems, as well as its characterization with over-the-air (OTA) multi-sine techniques. The 3D antenna consists of 15 antenna elements attached to an alternative 3D structure, allowing energy to be transmitted to all azimuth directions at different elevation angles without moving. The OTA multi-sine characterization technique was first utilized to identify issues in antenna arrays. However, in this work, the technique is used to identify which elements of the 3D antenna should operate to transmit the energy in a specific direction. Besides, the 3D antenna design description and its characterization are performed to authenticate its operation. Since 3D antennas are an advantage in WPT applications, the antenna is evaluated in a real WPT scenario to power an RF\u2013DC converter, and experimental results are presented.<\/jats:p>","DOI":"10.3390\/s21134461","type":"journal-article","created":{"date-parts":[[2021,6,29]],"date-time":"2021-06-29T22:39:43Z","timestamp":1625006383000},"page":"4461","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["3D Antenna Characterization for WPT Applications"],"prefix":"10.3390","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-5791-4602","authenticated-orcid":false,"given":"Marina","family":"Jord\u00e3o","sequence":"first","affiliation":[{"name":"Instituto de Telecomunica\u00e7\u00f5es, Departamento de Eletr\u00f3nica, Telecomunica\u00e7\u00f5es e Inform\u00e1tica, Universidade de Aveiro, Campus Universit\u00e1rio de Santiago, 3810-193 Aveiro, Portugal"}]},{"given":"Diogo","family":"Pires","sequence":"additional","affiliation":[{"name":"Instituto de Telecomunica\u00e7\u00f5es, Departamento de Eletr\u00f3nica, Telecomunica\u00e7\u00f5es e Inform\u00e1tica, Universidade de Aveiro, Campus Universit\u00e1rio de Santiago, 3810-193 Aveiro, Portugal"}]},{"given":"Daniel","family":"Belo","sequence":"additional","affiliation":[{"name":"Instituto de Telecomunica\u00e7\u00f5es, Departamento de Eletr\u00f3nica, Telecomunica\u00e7\u00f5es e Inform\u00e1tica, Universidade de Aveiro, Campus Universit\u00e1rio de Santiago, 3810-193 Aveiro, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5588-7794","authenticated-orcid":false,"given":"Pedro","family":"Pinho","sequence":"additional","affiliation":[{"name":"Instituto de Telecomunica\u00e7\u00f5es, 3810-193 Aveiro, Portugal"},{"name":"ISEL\u2014Instituto Superior de Engenharia de Lisboa, Instituto Polit\u00e9cnico de Lisboa, 1959-007 Lisboa, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7402-2099","authenticated-orcid":false,"given":"Nuno Borges","family":"Carvalho","sequence":"additional","affiliation":[{"name":"Instituto de Telecomunica\u00e7\u00f5es, Departamento de Eletr\u00f3nica, Telecomunica\u00e7\u00f5es e Inform\u00e1tica, Universidade de Aveiro, Campus Universit\u00e1rio de Santiago, 3810-193 Aveiro, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2021,6,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2787","DOI":"10.1016\/j.comnet.2010.05.010","article-title":"The Internet of Things: A Survey","volume":"54","author":"Luigi","year":"2010","journal-title":"Comput. 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