Simulation and Implementation of Distributed Microwave Wireless Power Transfer System

Tanaka, Yuki; Hamase, Hikaru; Kanai, Kaname; Hasaba, Ryosuke; Satō, Hiroshi; Koyanagi, Yoshio; Ikeda, Takuma; Tani, Hiroyuki; Gokan, Manabu; Kajiwara, Shoichi; Shinohara, Naoki

doi:10.1109/tmtt.2022.3142259

Cited by 11 publications

(3 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As obvious from (15), the maximum value of the FoM is equal to the maximum eigenvalue λ max of the Hermitian matrix M in (16) as…”

Section: Appendix a Derivation Of Optimal Human-aware Energy Bf Weightmentioning

confidence: 99%

“…Distributed antenna-based MWPT (DA-MWPT) employs multiple Txs at intervals much larger than the wavelength, enabling a wide-coverage power supply [14]- [16]. For DA-MWPT, optimal multi-Tx management activities, such as on/off switching [17], power adjustment [18], task scheduling [19], and antenna placement [20], have been proposed to maximize the total received power in the system while maintaining the EMF below a predetermined value in the area of interest.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Human-Aware Energy Beamforming for Microwave Wireless Power Transfer

Murata,

Kaneko,

Muramatsu

et al. 2024

Preprint

View full text Add to dashboard Cite

This paper proposes a novel human-aware energy beamforming (BF) method for safe and secure microwave wireless power transfer (MWPT). The proposed method first estimates an equivalent channel between a transmitting array antenna and a human body from continuous-wave pilot signals Doppler-shifted by human vital activities by utilizing the MWPT system as a quasi-monostatic multiple-input multiple-output (or single-output) radar. This allows the online estimation of the radio frequency (RF) exposure power without prior human geometry information. Then, the closed-form optimum BF weight can be derived to maximize the figure of merit (FoM), defined as the ratio of the received power to exposure power in the form of a generalized Rayleigh quotient. This simultaneously facilitates the suppression of RF exposure and enhancement of transfer efficiency. Comprehensive experiments were conducted to evaluate the proposed BF performance using our multi-antenna testbed with proven applicability to various human-sensing experiments. The indoor experiment proved that the proposed method performs null steering auto-tuned to human positions within a distance of up to 3 m and to the physical characteristics of six subjects, even under realistic conditions with multipath fading and array error. It achieved the highest FoM of 21.65 dB among conventional BF methods for a typical case. This was an improvement of 7.10 dB when compared with the result of maximum ratio transmission BF, which maximizes the transfer efficiency. This study demonstrates the possibility of coexistence of humanity and MWPT technology for its future social implementation.

show abstract

“…As obvious from (15), the maximum value of the FoM is equal to the maximum eigenvalue λ max of the Hermitian matrix M in (16) as…”

Section: Appendix a Derivation Of Optimal Human-aware Energy Bf Weightmentioning

confidence: 99%

mentioning

confidence: 99%

Human-Aware Energy Beamforming for Microwave Wireless Power Transfer

Murata,

Kaneko,

Muramatsu

et al. 2024

Preprint

View full text Add to dashboard Cite

show abstract

“…On the other hand, long-distance WPT has two ways: microwave and optical light. The microwave method incorporates electromagnetic waves from 10 cm to 0.1 mm (about 0.1 GHz to 100 GHz) [2]. However, high-power electromagnetic waves have the problem of causing electromagnetic interference.…”

Section: Introductionmentioning

confidence: 99%

Optical Wireless Power Transmission Using a GaInP Power Converter Cell under High-Power 635 nm Laser Irradiation of 53.5 W/cm2

et al. 2022

View full text Add to dashboard Cite

Optical wireless power transmission (OWPT) system is a technology that supplies energy from remote locations, having some features such as long-distance transmission, high directivity, and no electromagnetic noise interference. This study investigated the optical transmission efficiency and photoelectric conversion efficiency with a transmission distance of 10 m using GaInP power converter cells with a small area of 2.40 × 2.40 mm2 and a 635 nm high-power laser over 50 W/cm2. As a result, we achieved a photoelectric conversion efficiency of 44.7% under 6.7 W/cm2 (0.14 W) and 37.2% under 53.5 W/cm2 (1.1 W) irradiation. These results suggested that W-class optical wireless power transmission could be realized by expanding the converter cell area. Additionally, it was found that the reductions of the divergence angle of the laser and the heat generation of the power converter cell were critical issues for further lengthening the distance and increasing the power.

show abstract