10,054 research outputs found
Waveform Design for Wireless Power Transfer with Power Amplifier and Energy Harvester Non-Linearities
Waveform optimization has shown its great potential to boost the performance
of far-field wireless power transfer (WPT). Current research has optimized
transmit waveform, adaptive to channel state information (CSI), to maximize the
harvested power in WPT while accounting for energy harvester (EH)'s
non-linearity. However, the existing transmit waveform design disregards the
non-linear high power amplifiers (HPA) at the transmitter. Driven by this, this
paper optimizes the multi-carrier waveform at the input of HPA to maximize the
harvested DC power considering both HPA's and EH's non-linearities. Two
optimization models are formulated based on whether the frequencies of the
multi-carrier waveform are concentrated within the transmit pass band or not.
Analysis and simulations show that, while EH's non-linearity boosts the power
harvesting performance, HPA's non-linearity degrades the harvested power.
Hence, the optimal waveform shifts from multi-carrier that exploits EH's
non-linearity to single-carrier that reduces HPA's detrimental non-linear
distortion as the operational regime of WPT becomes more sensitive to HPA's
non-linearity and less sensitive to EH's non-linearity (and inversely).
Simultaneously, operating towards HPA's non-linear regime by increasing the
input signal power benefits the harvested power since HPA's DC power supply is
better exploited, whereas the end-to-end power transfer efficiency (PTE) might
decrease because of the increasing non-linear degradation. Throughout the
simulations, the proposed waveforms show significant gain over those not
accounting for HPA's non-linearity, especially in frequency-flat channels. We
also compare the two proposed waveforms and show that the severity of HPA's
non-linearity dictates which of the two proposed waveforms is more beneficial.Comment: 13 pages, 11 figures, submitted for potential publicatio
Waveform and Beamforming Design for Intelligent Reflecting Surface Aided Wireless Power Transfer: Single-User and Multi-User Solutions
In this paper, we study the waveform and passive beamforming design for
intelligent reflecting surface (IRS)-aided wireless power transfer (WPT).
Generalized multi-user and low complexity single-user algorithms are derived
based on alternating optimization (AO) framework to maximize the weighted sum
output DC current, subject to transmit power constraints and passive
beamforming phases unit modulus constraints. The input signal waveform and IRS
passive beamforming phase shifts are jointly designed as a function of users'
individual frequency-selective channel state information (CSI). The energy
harvester nonlinearity is explored and two IRS deployment schemes, namely
frequency selective IRS (FS-IRS) and frequency flat IRS (FF-IRS), are modeled
and analyzed. This paper highlights the fact that IRS can provide an extra
passive beamforming gain on output DC power over conventional WPT designs and
significantly influence the waveform design by leveraging the benefit of
passive beamforming, frequency diversity and energy harvester nonlinearity.
Even though FF-IRS exhibits lower output DC current than FS-IRS, it still
achieves substantially increased DC power over conventional WPT designs.
Performance evaluations confirm the significant benefits of a joint waveform
and passive beamforming design accounting for the energy harvester nonlinearity
to boost the performance of single-user and multi-user WPT system.Comment: 32 pages, 19 figures, submitted for publicatio
A GaN-based wireless power and information transmission method using Dual-frequency Programmed Harmonic Modulation
Information transmission is often required in power transfer to implement control. In this paper, a Dual-Frequency Programmed Harmonic Modulation (DFPHM) method is proposed to transfer two frequencies carrying power and information with the single converter via a common inductive coil. The proposed method reduces the number of injection tightly coupled transformers used to transmit information, thereby simplifying the system structure and improving reliability. The performances of power and information transmission, and the method of information modulation and demodulation, as well as the principles of the control, are analyzed in detail. Then a simulation model is set up to verify the feasibility of the method. In addition, an experiment platform is established to verify that the single converter can transfer the power and information simultaneously via a common inductive coil without using tightly coupled transformers.Web of Science8498564984
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