{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,6]],"date-time":"2026-05-06T16:37:27Z","timestamp":1778085447760,"version":"3.51.4"},"reference-count":32,"publisher":"MDPI AG","issue":"13","license":[{"start":{"date-parts":[[2024,6,28]],"date-time":"2024-06-28T00:00:00Z","timestamp":1719532800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Portuguese Foundation for Science and Technology, European Regional Development Fund (ERDF), through COMPETE 2020","award":["PTDC\/EEI-TEL\/29670\/2017\u2014(POCI-01-0145-FEDER-029670)"],"award-info":[{"award-number":["PTDC\/EEI-TEL\/29670\/2017\u2014(POCI-01-0145-FEDER-029670)"]}]},{"name":"Portuguese Foundation for Science and Technology, European Regional Development Fund (ERDF), through COMPETE 2020","award":["SFRH\/BD\/141462\/2018"],"award-info":[{"award-number":["SFRH\/BD\/141462\/2018"]}]},{"name":"Portuguese Foundation for Science and Technology, European Regional Development Fund (ERDF), through COMPETE 2020","award":["SFRH\/BD\/116554\/2016"],"award-info":[{"award-number":["SFRH\/BD\/116554\/2016"]}]},{"name":"Portuguese Foundation for Science and Technology, European Regional Development Fund (ERDF), through COMPETE 2020","award":["UIDB\/04436\/2020"],"award-info":[{"award-number":["UIDB\/04436\/2020"]}]},{"name":"Portuguese Foundation for Science and Technology, European Regional Development Fund (ERDF), through COMPETE 2020","award":["UIDP\/04436\/2020"],"award-info":[{"award-number":["UIDP\/04436\/2020"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Electronics"],"abstract":"<jats:p>Wireless technologies are revolutionizing communications, with recent deployments, such as 5G, playing a key role in the future of the Internet of Things (IoT). Such progress is leading to an increasingly higher number of wirelessly connected devices. These require increased battery use and maintenance, consequently straining current powering solutions. Since most wireless systems rely on radiofrequency (RF) waves for communications and feature low-power technologies, it is increasingly feasible to develop and implement wireless power transfer solutions supported by RF. In this paper, a simultaneous wireless information and power transfer (SWIPT) solution targeting small mobile devices is presented. This solution uses beamforming to mitigate the path loss associated with the RF power propagation. It relies on an RF backscattering tracking algorithm to power moving devices. The feasibility to power wearable devices is demonstrated by tracking a walking individual (approximately 5 km\/h) at a distance of 0.5 m while transferring a minimum of 6 dBm to a wearable device using 2 GHz RF signals. Simulations were used to determine the viability of such a solution to deliver useful power levels to a 1.2 \u00d7 1.4 m2 working area without exceeding specific absorption rate (SAR) limits.<\/jats:p>","DOI":"10.3390\/electronics13132550","type":"journal-article","created":{"date-parts":[[2024,7,1]],"date-time":"2024-07-01T08:17:29Z","timestamp":1719821849000},"page":"2550","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Long-Range Wireless Power Transfer for Moving Wireless IoT Devices"],"prefix":"10.3390","volume":"13","author":[{"given":"Ivo","family":"Colmiais","sequence":"first","affiliation":[{"name":"Center for MicroElectromechanical Systems (CMEMS-Uminho), University of Minho, 4800-058 Guimar\u00e3es, Portugal"},{"name":"LABBELS\u2013Associate Laboratory, 4710-057 Braga, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2394-2119","authenticated-orcid":false,"given":"Hugo","family":"Dinis","sequence":"additional","affiliation":[{"name":"Center for MicroElectromechanical Systems (CMEMS-Uminho), University of Minho, 4800-058 Guimar\u00e3es, Portugal"},{"name":"LABBELS\u2013Associate Laboratory, 4710-057 Braga, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2177-7321","authenticated-orcid":false,"given":"Paulo M.","family":"Mendes","sequence":"additional","affiliation":[{"name":"Center for MicroElectromechanical Systems (CMEMS-Uminho), University of Minho, 4800-058 Guimar\u00e3es, Portugal"},{"name":"LABBELS\u2013Associate Laboratory, 4710-057 Braga, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2024,6,28]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"16","DOI":"10.1109\/JIOT.2019.2948888","article-title":"A Comprehensive Survey on Internet of Things (IoT) Toward 5G Wireless Systems","volume":"7","author":"Chettri","year":"2020","journal-title":"IEEE Internet Things J."},{"key":"ref_2","unstructured":"Collela, P. (2024, May 03). 5G and IoT: Ushering in a New Era. Available online: https:\/\/www.livemint.com\/Opinion\/SktcUSRU6iMQ7BNUknwbFK\/5G-and-IoT-Ushering-in-a-new-era.html."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"4","DOI":"10.1109\/JSAC.2018.2872615","article-title":"Fundamentals of Wireless Information and Power Transfer: From RF Energy Harvester Models to Signal and System Designs","volume":"37","author":"Clerckx","year":"2019","journal-title":"IEEE J. Sel. Areas Commun."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"8956","DOI":"10.1109\/TIE.2018.2811360","article-title":"A Self-Powered 3.26-\u039cW 70-Meter Wireless Temperature Sensor Node for Power Grid Monitoring","volume":"65","author":"Chen","year":"2018","journal-title":"IEEE Trans. Ind. Electron."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1529","DOI":"10.1109\/TCSI.2017.2758327","article-title":"An RF-Powered Wireless Temperature Sensor for Harsh Environment Monitoring with Non-Intermittent Operation","volume":"65","author":"Saffari","year":"2018","journal-title":"IEEE Trans. Circuits Syst. I Regul. Pap."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1682","DOI":"10.1109\/JSSC.2014.2325574","article-title":"A Fully-Integrated 71 NW CMOS Temperature Sensor for Low Power Wireless Sensor Nodes","volume":"49","author":"Jeong","year":"2014","journal-title":"IEEE J. Solid-State Circuits"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"7889","DOI":"10.1109\/JSEN.2018.2861431","article-title":"A UW Backscatter-Morse-Leaf Sensor for Low-Power Agricultural Wireless Sensor Networks","volume":"18","author":"Daskalakis","year":"2018","journal-title":"IEEE Sens. J."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Dinis, H., and Mendes, P.M. (2021). A Comprehensive Review of Powering Methods Used in State-of-the-Art Miniaturized Implantable Electronic Devices. Biosens. Bioelectron., 172.","DOI":"10.1016\/j.bios.2020.112781"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"2996","DOI":"10.1109\/JIOT.2020.2964302","article-title":"Simultaneous Wireless Information and Power Transfer (SWIPT) for Internet of Things: Novel Receiver Design and Experimental Validation","volume":"7","author":"Choi","year":"2020","journal-title":"IEEE Internet Things J."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"2510","DOI":"10.1109\/TIE.2020.2973903","article-title":"Retroreflective Transceiver Array Using a Novel Calibration Method Based on Optimum Phase Searching","volume":"68","author":"Koo","year":"2021","journal-title":"IEEE Trans. Ind. Electron."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"7481","DOI":"10.1109\/TIE.2021.3102453","article-title":"Wall-Meshed Cavity Resonator Based Wireless Power Transfer without Blocking Wireless Communications with Outside World","volume":"69","author":"Yue","year":"2021","journal-title":"IEEE Trans. Ind. Electron."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"125","DOI":"10.1109\/MMM.2017.2664001","article-title":"Energizing 5G: Near- and Far-Field Wireless Energy and Data Trantransfer as an Enabling Technology for the 5G IoT","volume":"18","author":"Costanzo","year":"2017","journal-title":"IEEE Microw. Mag."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"310","DOI":"10.1109\/JIOT.2017.2782367","article-title":"Wireless Powered Sensor Networks for Internet of Things: Maximum Throughput and Optimal Power Allocation","volume":"5","author":"Chu","year":"2018","journal-title":"IEEE Internet Things J."},{"key":"ref_14","first-page":"6881","article-title":"Redefining the Channel Bandwidth for Simultaneous Wireless Power and Information Transfer","volume":"69","author":"Zhou","year":"2021","journal-title":"IEEE Trans. Ind. Electron."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"4013","DOI":"10.1109\/TIE.2018.2831196","article-title":"Simultaneous Wireless Power and Bidirectional Information Transmission with a Single-Coil, Dual-Resonant Structure","volume":"66","author":"Ji","year":"2019","journal-title":"IEEE Trans. Ind. Electron."},{"key":"ref_16","unstructured":"Arampatzis, T., Lygeros, J., and Manesis, S. (2005, January 27\u201329). A Survey of Applications of Wireless Sensors and Wireless Sensor Networks. Proceedings of the 2005 IEEE International Symposium on, Mediterrean Conference on Control and Automation Intelligent Control, Limassol, Cyprus."},{"key":"ref_17","unstructured":"(2024, May 03). I-Grape. Available online: https:\/\/i-grape.eu\/."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Li, C.M., Nien, C.C., Liao, J.L., and Tseng, Y.C. (2012, January 11\u201316). Development of Wireless Sensor Module and Network for Temperature Monitoring in Cold Chain Logistics. Proceedings of the 2012 IEEE International Conference on Wireless Information Technology and Systems (ICWITS), Maui, HI, USA.","DOI":"10.1109\/ICWITS.2012.6417745"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1400063","DOI":"10.1002\/aelm.201400063","article-title":"Highly Stretchy Black Gold E-Skin Nanopatches as Highly Sensitive Wearable Biomedical Sensors","volume":"1","author":"Gong","year":"2015","journal-title":"Adv. Electron. Mater."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"763","DOI":"10.1038\/ncomms1767","article-title":"Graphene-Based Wireless Bacteria Detection on Tooth Enamel","volume":"3","author":"Mannoor","year":"2012","journal-title":"Nat. Commun."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Jeong, H., Ha, T., Kuang, I., Shen, L., Dai, Z., Sun, N., and Lu, N. (2017, January 11\u201315). NFC-Enabled, Tattoo-like Stretchable Biosensor Manufactured by \u201ccut-and-Paste\u201d Method. Proceedings of the 2017 39th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), Jeju, Republic of Korea.","DOI":"10.1109\/EMBC.2017.8037756"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"4754","DOI":"10.1109\/TCOMM.2013.13.120855","article-title":"Wireless Information and Power Transfer : Architecture Design and Rate-Energy Tradeoff","volume":"61","author":"Design","year":"2013","journal-title":"IEEE Trans. Commun."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1422","DOI":"10.1109\/TBME.2017.2668612","article-title":"A Review of In-Body Biotelemetry Devices: Implantables, Ingestibles, and Injectables","volume":"64","author":"Kiourti","year":"2017","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"7460","DOI":"10.1109\/JSEN.2019.2915299","article-title":"Optimal Design of Passive Resonating Wireless Sensors for Wearable and Implantable Devices","volume":"19","author":"Yeon","year":"2019","journal-title":"IEEE Sens. J."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"822","DOI":"10.1109\/JMEMS.2016.2602298","article-title":"LC Passive Wireless Sensors Toward a Wireless Sensing Platform: Status, Prospects, and Challenges","volume":"25","author":"Huang","year":"2016","journal-title":"J. Microelectromech. Syst."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Jia, W., Jiang, H., Yang, X., Wang, W., Wang, Z., Wang, J.J., and Wu, Y. (2019, January 17\u201319). Passive Implantable Wireless Intracranial Pressure Monitoring Based on Near Field Communication. Proceedings of the 2019 IEEE Biomedical Circuits and Systems Conference (BioCAS), Nara, Japan.","DOI":"10.1109\/BIOCAS.2019.8919064"},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Park, J., Kim, J.-K., Patil, S., Park, J.-K., Park, S., and Lee, D.-W. (2016). A Wireless Pressure Sensor Integrated with a Biodegradable Polymer Stent for Biomedical Applications. Sensors, 16.","DOI":"10.3390\/s16060809"},{"key":"ref_28","unstructured":"Balanis, C.A. (2005). Antenna Theory: Analysis and Design, John Wiley and Sons, Inc.. [3rd ed.]."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"191","DOI":"10.1016\/S0377-0427(00)00423-4","article-title":"Direct Search Methods: Then and Now","volume":"124","author":"Lewis","year":"2000","journal-title":"J. Comput. Appl. Math."},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Colmiais, I., Dinis, H., and Mendes, P.M. (2019, January 22\u201323). WPT System for Implantable Devices Using a Phased Array and Tracking Algorithm for Freely Moving Rats. Proceedings of the IEEE 6th Portuguese Meeting on Bioengineering (ENBENG), Lisbon, Portugal.","DOI":"10.1109\/ENBENG.2019.8692495"},{"key":"ref_31","unstructured":"Standards, I., and Committee, C. (2019). IEEE Standard for Safety Levels with Respect to Human Exposure to Electric, Magnetic, and Electromagnetic Fields, 0 Hz to 300 GHz, IEEE. IEEE Standard for Safety Levels with Respect to Human Exposure to Electric, Magnetic, and Electromagnet."},{"key":"ref_32","unstructured":"FCC (1997). OET Bulletin 65: Evaluating Compliance with FCC Guidelines for Human Exposure to Radiofrequency Electromagnetic Fields, FCC."}],"container-title":["Electronics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2079-9292\/13\/13\/2550\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T15:07:09Z","timestamp":1760108829000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2079-9292\/13\/13\/2550"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,6,28]]},"references-count":32,"journal-issue":{"issue":"13","published-online":{"date-parts":[[2024,7]]}},"alternative-id":["electronics13132550"],"URL":"https:\/\/doi.org\/10.3390\/electronics13132550","relation":{},"ISSN":["2079-9292"],"issn-type":[{"value":"2079-9292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,6,28]]}}}