A Multifocus Technique for Multitarget Microwave Wireless Power Transfer Applications

This paper proposes a multifocus technique to supply power to multiple targets in microwave wireless power transfer (MWPT) applications. A phase expression is derived to precisely adjust the direction and focal length of the formed focal spot. Furthermore, a distance-weighted multifocus shared-aperture (DWMFSA) method is introduced to reconstruct phase distribution over the transmitter to form multiple focal. The calculation phase distribution shows the proposed method maximally preserves the features of the original single-focal phase distribution. The experimental results show that the minimum errors in direction control between the measured and theoretical values are 0.8° and 1.5° for the proposed and traditional methods, respectively. For focal length adjustment, the maximum error is 17.0 mm with the proposed method, whereas the traditional approach results in an error of 36.0 mm. Additionally, the proposed DWMFSA method can increase the measured power by 17.3% compared to the conventional approach. Furthermore, there is reason to believe it can be applied in multitarget MWPT scenarios.