Microwave power transfer (MPT) has emerged as a method of wireless power transmission for Internet of Things (IoT) devices. A rectifying antenna can convert microwaves into power for the devices while simultaneously facilitating data communication. While most research has focused on efficient power transfer for a single IoT device, there have been few studies considering scenarios involving multiple IoT devices. This paper proposes an efficient and fair MPT system for multiple IoT devices: more delivered power at the same transmit budget; more even per-device satisfaction with worst-user protection. The proposed system achieves both efficiency and fairness by mitigating power attenuation for each IoT device and optimizing power distribution based on the varying demands of IoT devices. Our results demonstrated that the proposed system outperformed an existing system in terms of both efficiency and fairness for each IoT device.
Yamaguchi et al. (2026) studied this question.