Near-/Intermediate-Field Region WPT Framework via Plane-Wave Generation for Spatially Uniform Power Delivery

초록

This communication presents a near-field wireless power transfer (WPT) framework for achieving spatially uniform power delivery using a plane-wave generation (PWG) approach. Unlike conventional near-field focusing (NFF), which produces spherical wavefronts and localized power concentration, the proposed method synthesizes quasi-plane waves by optimizing the transmit-array excitation coefficients through a ridge regression formulation. Under a perfectly aligned reference configuration, PWG and NFF are compared in terms of RF-domain transfer efficiency and received-power variation across the receiver array. Fabricated Tx and Rx arrays are characterized through pairwise S-parameter measurements, and the measured channel matrix is used to reconstruct the RF received-power distributions. The reconstructed RF powers are further mapped through a separately measured 5.8-GHz rectifier response to estimate the rectified-voltage distribution. These results show that PWG improves RF-domain spatial uniformity and can stabilize the rectifier operating points across the receiving array. Owing to its optimization-based and array-compatible nature, PWG provides a practical and reconfigurable strategy for uniform near-/intermediate-field WPT.

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