A 24-GHz 4-Element Multi-Beam Wireless Energy Harvesting Array with Class-F Rectifiers Achieving 51.5% PCE

This study introduces a 24GHz 4-element concurrent multi-beam energy harvesting array, distinguished by the implementation of a novel three-line-coupler to simultaneously perform matching and harmonic shaping, achieving the best reported rectifier power conversion efficiency (PCE) of 51.5%. A 4-port ultra-compact Butler matrix with transformer-based 90° hybrid couplers is utilized to develop concurrent coherent beamforming. Fabricated in a 22nm CMOS FD-SOI process with a total core area of 0.53mm
²
, the proposed array can cover the full field of view (FoV) with 28dB peak-to-null ratio and 30.2% system efficiency. The proposed architecture offers a compact, efficient solution, which can significantly enhance the performance of mm-Wave wireless power transfer (WPT) links.