Broadband Compact Substrate-Independent Textile Wearable Antenna for Simultaneous Near- and Far-Field Wireless Power Transmission

Despite an increasing interest in wearable wireless power transmission (WPT), until now, wearable antennas have been unable to simultaneously harvest from near-field resonant and far-field radiative WPT. Here, a dual-port antenna is proposed, integrating an inductive coil with a broadband monopole f...

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Main Authors: Mahmoud Wagih, Abiodun Komolafe, Alex S. Weddell, Steve Beeby
Format: Article
Language:English
Published: IEEE 2022-01-01
Series:IEEE Open Journal of Antennas and Propagation
Subjects:
Online Access:https://ieeexplore.ieee.org/document/9756543/
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author Mahmoud Wagih
Abiodun Komolafe
Alex S. Weddell
Steve Beeby
author_facet Mahmoud Wagih
Abiodun Komolafe
Alex S. Weddell
Steve Beeby
author_sort Mahmoud Wagih
collection DOAJ
description Despite an increasing interest in wearable wireless power transmission (WPT), until now, wearable antennas have been unable to simultaneously harvest from near-field resonant and far-field radiative WPT. Here, a dual-port antenna is proposed, integrating an inductive coil with a broadband monopole for near- and far-field wearable WPT. The coil acts simultaneously as a High Frequency (HF) near-field power receiver and an Ultra-High Frequency (UHF) resonator, enabling the miniaturization of the enclosed broadband monopole, both fabricated using all-textile conductors. On-body, the antenna maintains a 10 dB return loss over a measured 135&#x0025; fractional bandwidth while maintaining compactness (<inline-formula> <tex-math notation="LaTeX">$0.312\times 0.312\lambda ^{2}$ </tex-math></inline-formula>). The antenna is substrate-independent and is demonstrated on two textile substrates with different dielectric properties and thicknesses. In far-field mode, the rectenna maintains over 40&#x0025; efficiency from sub-1 <inline-formula> <tex-math notation="LaTeX">$\mu \text{W}$ </tex-math></inline-formula>/cm<sup>2</sup> power densities. In the near-field, a WPT efficiency up to 80&#x0025; can be achieved. The simulated Specific Absorption Rate (SAR) shows up to 40 and 20 dBm power reception for HF and UHF operation, respectively, without exceeding the 1.7 W/kg limit. The far-field wearable rectenna is demonstrated powering a Bluetooth Low Energy node using a BQ25504 DC-DC converter from a best-in-class low power density of 0.88 and <inline-formula> <tex-math notation="LaTeX">$0.55~\mu \text{W}$ </tex-math></inline-formula>/cm<sup>2</sup> on-body and in-space, respectively.
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spelling doaj.art-639f559fd5e1451e8ac6e0df344e22b12022-12-22T01:53:27ZengIEEEIEEE Open Journal of Antennas and Propagation2637-64312022-01-01339841110.1109/OJAP.2022.31670899756543Broadband Compact Substrate-Independent Textile Wearable Antenna for Simultaneous Near- and Far-Field Wireless Power TransmissionMahmoud Wagih0https://orcid.org/0000-0002-7806-4333Abiodun Komolafe1https://orcid.org/0000-0002-3618-2390Alex S. Weddell2https://orcid.org/0000-0002-6763-5460Steve Beeby3https://orcid.org/0000-0002-0800-1759School of Electronics and Computer Science, University of Southampton, Southampton, U.K.School of Electronics and Computer Science, University of Southampton, Southampton, U.K.School of Electronics and Computer Science, University of Southampton, Southampton, U.K.School of Electronics and Computer Science, University of Southampton, Southampton, U.K.Despite an increasing interest in wearable wireless power transmission (WPT), until now, wearable antennas have been unable to simultaneously harvest from near-field resonant and far-field radiative WPT. Here, a dual-port antenna is proposed, integrating an inductive coil with a broadband monopole for near- and far-field wearable WPT. The coil acts simultaneously as a High Frequency (HF) near-field power receiver and an Ultra-High Frequency (UHF) resonator, enabling the miniaturization of the enclosed broadband monopole, both fabricated using all-textile conductors. On-body, the antenna maintains a 10 dB return loss over a measured 135&#x0025; fractional bandwidth while maintaining compactness (<inline-formula> <tex-math notation="LaTeX">$0.312\times 0.312\lambda ^{2}$ </tex-math></inline-formula>). The antenna is substrate-independent and is demonstrated on two textile substrates with different dielectric properties and thicknesses. In far-field mode, the rectenna maintains over 40&#x0025; efficiency from sub-1 <inline-formula> <tex-math notation="LaTeX">$\mu \text{W}$ </tex-math></inline-formula>/cm<sup>2</sup> power densities. In the near-field, a WPT efficiency up to 80&#x0025; can be achieved. The simulated Specific Absorption Rate (SAR) shows up to 40 and 20 dBm power reception for HF and UHF operation, respectively, without exceeding the 1.7 W/kg limit. The far-field wearable rectenna is demonstrated powering a Bluetooth Low Energy node using a BQ25504 DC-DC converter from a best-in-class low power density of 0.88 and <inline-formula> <tex-math notation="LaTeX">$0.55~\mu \text{W}$ </tex-math></inline-formula>/cm<sup>2</sup> on-body and in-space, respectively.https://ieeexplore.ieee.org/document/9756543/Antennasbody area networkscoilsinductorsrectennasrectifiers
spellingShingle Mahmoud Wagih
Abiodun Komolafe
Alex S. Weddell
Steve Beeby
Broadband Compact Substrate-Independent Textile Wearable Antenna for Simultaneous Near- and Far-Field Wireless Power Transmission
IEEE Open Journal of Antennas and Propagation
Antennas
body area networks
coils
inductors
rectennas
rectifiers
title Broadband Compact Substrate-Independent Textile Wearable Antenna for Simultaneous Near- and Far-Field Wireless Power Transmission
title_full Broadband Compact Substrate-Independent Textile Wearable Antenna for Simultaneous Near- and Far-Field Wireless Power Transmission
title_fullStr Broadband Compact Substrate-Independent Textile Wearable Antenna for Simultaneous Near- and Far-Field Wireless Power Transmission
title_full_unstemmed Broadband Compact Substrate-Independent Textile Wearable Antenna for Simultaneous Near- and Far-Field Wireless Power Transmission
title_short Broadband Compact Substrate-Independent Textile Wearable Antenna for Simultaneous Near- and Far-Field Wireless Power Transmission
title_sort broadband compact substrate independent textile wearable antenna for simultaneous near and far field wireless power transmission
topic Antennas
body area networks
coils
inductors
rectennas
rectifiers
url https://ieeexplore.ieee.org/document/9756543/
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AT alexsweddell broadbandcompactsubstrateindependenttextilewearableantennaforsimultaneousnearandfarfieldwirelesspowertransmission
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