Omnidirectional dual-polarized low-profile textile rectenna with over 50% efficiency for sub-μW/cm2 wearable power harvesting

Wagih, M. , Weddell, A. S. and Beeby, S. (2021) Omnidirectional dual-polarized low-profile textile rectenna with over 50% efficiency for sub-μW/cm2 wearable power harvesting. IEEE Transactions on Antennas and Propagation, 69(5), pp. 2522-2536. (doi: 10.1109/TAP.2020.3030992)

Abstract

Despite the recent advances in textile antennas, in complete systems such as a rectenna, the efficiency of fully textile solutions has been over 46% lower than hybrid textile/rigid implementations. This article presents a fully textile rectenna for ultralow-power sub- μW/cm 2 applications. A dual-polarized omnidirectional low-profile textile antenna is presented. The rectenna is based on a compact inductively matched rectifier. The textile-based rectifier occupies 0.22 cm 2 and achieves a state-of-the-art power conversion efficiency (PCE) of 41.8% at -20 dBm, at 820 MHz, despite its lossy substrate. A triple-band rectifier is then designed and fabricated to show the scalability of the matching approach. The rectifier is characterized using a new figure of merit “average PCE” over a time period while charging a capacitor. Time-varying S-parameters are used to quantify the impact of the capacitor's charge on the impedance matching. The rectifier directly charges a 1.32 mF capacitor up to 1 V in 0.41 and 4.5 s from 10 and 0 dBm, respectively. Wireless testing of the proposed rectenna demonstrates over 50% and 40% (PCE) below 1 μW/cm 2 in space and on-body, respectively. The rectenna efficiently receives power from mismatched polarization and with a 360° half-power beamwidth.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Wagih, Dr Mahmoud
• Authors: Wagih, M., Weddell, A. S., and Beeby, S.
• College/School: College of Science and Engineering > School of Engineering > Systems Power and Energy
• Journal Name: IEEE Transactions on Antennas and Propagation
• Publisher: IEEE
• ISSN: 0018-926X
• ISSN (Online): 1558-2221
• Published Online: 20 October 2020
• Copyright Holders: Copyright © 2020 IEEE
• First Published: First published in IEEE Transactions on Antennas and Propagation 69(5): 2522-2536
• Publisher Policy: Reproduced in accordance with the publisher copyright policy
• Data DOI: 10.5258/SOTON/D1571