Experimental Study on the Effect of Synchronization Accuracy for Near-Field RF Wireless Power Transfer in Multi-Antenna Systems

Gilles Callebaut; Jarne Van Mulders; Bert Cox; Benjamin J. B. Deutschmann; Geoffrey Ottoy; Lieven De Strycker; Liesbet Van der Perre

arXiv · 2412.11116

Experimental Study on the Effect of Synchronization Accuracy for Near-Field RF Wireless Power Transfer in Multi-Antenna Systems

Gilles Callebaut·Jarne Van Mulders·Bert Cox·Benjamin J. B. Deutschmann·Geoffrey Ottoy·Lieven De Strycker·Liesbet Van der Perre

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Abstract

Wireless power transfer (WPT) technologies hold promise for enhancing device autonomy, particularly for energy-limited IoT systems. This paper presents experimental results on coherent and non-coherent transmit diversity approaches for WPT, tested in the near field using the Techtile testbed. We demonstrate that a fully synchronized beamfocusing system achieves a 14 dB gain over non-coherent transmission, consistent with the theoretical 14.9 dB gain for a 31-element array. Additionally, phase alignment errors below 20{\deg} result in less than 1 dB of gain loss, while errors exceeding 40{\deg} lead to losses over 3 dB. These findings suggest that phase coherency requirements for WPT can be relaxed, and that scaling the number of antennas is a promising strategy for improving power transfer efficiency.

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Gilles Callebaut, Jarne Van Mulders, Bert Cox, Benjamin J. B. Deutschmann, Geoffrey Ottoy, Lieven De Strycker, Liesbet Van der Perre. 2024-12-15. Experimental Study on the Effect of Synchronization Accuracy for Near-Field RF Wireless Power Transfer in Multi-Antenna Systems. https://arxiv.org/abs/2412.11116

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