Position Independent Wearable 6.78 MHz Near-Field Radiative Wireless Power Transfer using Electrically-Small Embroidered Textile Coils

Wagih, M. , Komolafe, A. O. and Zaghari, B. (2020) Position Independent Wearable 6.78 MHz Near-Field Radiative Wireless Power Transfer using Electrically-Small Embroidered Textile Coils. In: 2019 19th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS), Krakow, Poland, 02-06 Dec 2019, ISBN 9781728156385 (doi: 10.1109/PowerMEMS49317.2019.51289502905)

Abstract

Coupled wireless power transfer (WPT) has been widely used for near-field high-efficiency WPT applications. However, the efficiency of the WPT link is highly sensitive to separation and alignment, and is prone to over-coupling, making it unsuitable for mobile systems with unknown or loose coupling such as wearables. While ultra-high frequency (UHF) and microwave radiative WPT (0.3-3 GHz) enables meters-long separation between the transmitter and the receiver, free space propagation losses, and rectification inefficiencies, adversely limit the end-to-end efficiency of the WPT link. This work proposes radiative WPT, in the 6.78 MHz license-free band, based on resonant electrically small antennas fabricated using embroidered textile coils, tuned using L-matching networks. The proposed WPT system achieves a stable forward transmission of S 21 >-17 dB and S 21 >-28 dB, independent of coil, separation on the XZ and XY planes respectively, in a 27 m 3 volume space. The presented approach demonstrates the highest WPT-link efficiency, and promises higher end-to-end efficiency, compared to UHF WPT.

• Item Type: Conference Proceedings
• Additional Information: This work was supported by the UK Engineering and Physical Sciences Research Council (EPSRC) under Grant EP/P010164/1.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Wagih, Dr Mahmoud
• Authors: Wagih, M., Komolafe, A. O., and Zaghari, B.
• College/School: College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• Journal Name: PowerMEMS 2019, Krakow, Poland, 3/12/19
• ISBN: 9781728156385