One-to-Multiple RF Power Transmission System Based on High-Gain Phased Array with Beam Control

This paper proposes a one-to-multiple RF wireless power transmission (WPT) system that uses multi-mode phased array technology to control beamforming. The proposed system uses array partition mode and time division mode to achieve multi-target WPT. A novel quasi-Yagi antenna with enhanced gain is designed, consisting of a pair of dipoles, three directors, and a single split-ring resonator (SSRR), which is then used to form a 1×8 array for power transmission. The antenna has a bandwidth of 0.35 GHz with a frequency range of 2.25-2.6 GHz and a gain of 9.38 dBi. The total gain of the 1×8 array antenna is 17.23 dBi. An 8-way power divider is designed and implemented to feed the power amplifier (PA) of each array element, with isolation greater than 20 dB and return loss less than −17 dB. A digital phase and attenuation control circuit is also designed to achieve beam control. Measurement results show that at a distance of 3 meters, the maximum received power for single-target and multi-target schemes is 7.5 dBm and −2.6 dBm at each node, respectively. The system’s flexible beam control mode and high gain transmission characteristics can be used in scenarios such as wirelessly powering Internet of Things (IoT) multi-sensor networks.