Analysis, design and realization of a near-field focused RF power transfer system

Abstract

This paper reports the analysis, design, prototyping and first measurement results of a linear array antenna consisting of Yagi-Uda elements, rotated and phased for focusing RF power in the near-field of the antenna. By employing Near Field Focusing more power may be transmitted before the EIRP limit is reached due to the inherent far-field difusing. A design based on four Yagi-Uda array elements is able to produce an average power density of 21.04dBm/m2 at 2.45GHz in a box of 10×10×10cm3 located 1m from the linear array face. The design has been verified through comparison with full-wave electromagnetic simulations. First measurements on a realized prototype confirm the functioning of the array. © Published under licence by IOP Publishing Ltd.