On the beneficial roles of fading and transmit diversity in wireless power transfer with nonlinear energy harvesting
File(s)
Accepted version
Author(s)
Clerckx, B
Kim, J
Type
Journal Article
Abstract
We study the effect of channel fading in Wireless
Power Transfer (WPT) and show that fading enhances the RF-
to-DC conversion efficiency of nonlinear RF energy harvesters.
We then develop a new form of signal design for WPT, denoted as
Transmit Diversity, that relies on multiple dumb antennas at the
transmitter to induce fast fluctuations of the wireless channel.
Those fluctuations boost the RF-to-DC conversion efficiency
thanks to the energy harvester nonlinearity. In contrast with
(energy) beamforming, Transmit Diversity does not rely on
Channel State Information at the Transmitter (CSIT) and does
not increase the average power at the energy harvester input,
though it still enhances the overall end-to-end power transfer
efficiency. Transmit Diversity is also combined with recently
developed (energy) waveform and modulation to provide further
enhancements. The efficacy of the scheme is analyzed using
physics-based and curve fitting-based nonlinear models of the en-
ergy harvester and demonstrated using circuit simulations, pro-
totyping and experimentation. Measurements with two transmit
antennas reveal gains of 50% in harvested DC power over a single
transmit antenna setup. The work (again) highlights the crucial
role played by the harvester nonlinearity and demonstrates that
multiple transmit antennas can be beneficial to WPT even in the
absence of CSIT.
Power Transfer (WPT) and show that fading enhances the RF-
to-DC conversion efficiency of nonlinear RF energy harvesters.
We then develop a new form of signal design for WPT, denoted as
Transmit Diversity, that relies on multiple dumb antennas at the
transmitter to induce fast fluctuations of the wireless channel.
Those fluctuations boost the RF-to-DC conversion efficiency
thanks to the energy harvester nonlinearity. In contrast with
(energy) beamforming, Transmit Diversity does not rely on
Channel State Information at the Transmitter (CSIT) and does
not increase the average power at the energy harvester input,
though it still enhances the overall end-to-end power transfer
efficiency. Transmit Diversity is also combined with recently
developed (energy) waveform and modulation to provide further
enhancements. The efficacy of the scheme is analyzed using
physics-based and curve fitting-based nonlinear models of the en-
ergy harvester and demonstrated using circuit simulations, pro-
totyping and experimentation. Measurements with two transmit
antennas reveal gains of 50% in harvested DC power over a single
transmit antenna setup. The work (again) highlights the crucial
role played by the harvester nonlinearity and demonstrates that
multiple transmit antennas can be beneficial to WPT even in the
absence of CSIT.
Date Issued
2018-11-01
Date Acceptance
2018-09-01
Citation
IEEE Transactions on Wireless Communications, 2018, 17 (11), pp.7731-7743
ISSN
1536-1276
Publisher
Institute of Electrical and Electronics Engineers
Start Page
7731
End Page
7743
Journal / Book Title
IEEE Transactions on Wireless Communications
Volume
17
Issue
11
Copyright Statement
© 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.
Subjects
Science & Technology
Technology
Engineering, Electrical & Electronic
Telecommunications
Engineering
Fading
transmit diversity
energy modulation
energy waveform
energy beamforming
nonlinear energy harvesting
wireless power transfer
WAVE-FORM DESIGN
FEEDBACK
0906 Electrical And Electronic Engineering
1005 Communications Technologies
0805 Distributed Computing
Networking & Telecommunications
Publication Status
Published
Date Publish Online
2018-09-24