Distance-Insensitive Wireless Power Transfer and Near-Field Communication Using a Current-Controlled Loop With a Loaded Capacitance

• Published in: IEEE transactions on antennas and propagation Vol. 62; no. 2; pp. 936 - 940
• Main Authors: LEE, Wang-Sang, OH, Kyoung-Sub, YU, Jong-Won
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.02.2014; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Antennas; Applied sciences; Capacitance; Channels; Coils; Current-controlled; distance-insensitive; Exact sciences and technology; Impedance; Inductance; loaded capacitance; near-field communication (NFC); Power transfer; Radiocommunications; Radiolocalization and radionavigation; Receiving antennas; Services and terminals of telecommunications; Systems, networks and services of telecommunications; Telecommunications; Telecommunications and information theory; Telemetry. Remote supervision. Telewarning. Remote control; Transmission; Transmitting antennas; Tuning; Wireless communication; wireless power transfer (WPT); Range finding; Operating mode; distance-insensitive; wireless power transfer (WPT); Wireless electricity; Transfer coefficient; Mutual inductance; Algorithm; Mismatching; loaded capacitance; Transmitting antenna; Near field communication; Capacitance; Current-controlled; near-field communication (NFC); Receiving antenna; Radio frequency identification
• ISSN: 0018-926X; 1558-2221
• DOI: 10.1109/TAP.2013.2290549

Using a current-controlled loop with a loaded capacitance, we experimentally demonstrated distance-insensitive wireless power transfer (WPT) and near-field communication (NFC) without additional tuning network and algorithms. The proposed loop can achieve the uniform mutual inductance within the operating distance by controlling the ratio of the current flowing through the forward and reverse loops according to the loaded capacitance. By reducing the impedance mismatch within the operating distance ranging from 0 to 7 cm, the proposed loop can provide the transfer efficiency over approximately 60% for WPT and a stable channel bandwidth for NFC operating modes. In particular, when the receiving antenna is close proximity to the transmitting antenna, the transfer efficiency of the proposed loop is up to nearly six times higher than that of conventional loop.