Wirelessly Powered Relay Will Help Bring 5G Technology to Smart Factories: Assoc. Prof. Atsushi Shirane

A recently developed wirelessly powered 5G relay could accelerate the development of smart factories, report scientists from Tokyo Tech. By adopting a lower operating frequency for wireless power transfer, the proposed relay design solves many of the current limitations, including range and efficiency. In turn, this allows for a more versatile and widespread arrangement of sensors and transceivers in industrial settings.

To avoid relying on cumbersome wired power sources, sensors and transceivers can be energized remotely via wireless power transfer (WPT). However, one problem with conventional WPT designs is that they operate at 24 GHz. At such high frequencies, transmission beams must be extremely narrow to avoid energy losses. Moreover, power can only be transmitted if there is a clear line of sight between the WPT system and the target device. Since 5G relays are often used to extend the range of 5G base stations, WPT needs to reach even further, which is yet another challenge for 24 GHz systems.

To address the limitations of WPT, a research team from Tokyo Institute of Technology has come up with a clever solution. In a recent study, whose results have been presented in the 2024 IEEE Symposium on VLSI Technology & Circuits, they developed a novel 5G relay that can be powered wirelessly at a lower frequency of 5.7 GHz (as shown in Figure 1). "By using 5.7 GHz as the WPT frequency, we can get wider coverage than conventional 24 GHz WPT systems, enabling a wider range of devices to operate simultaneously," explains senior author and Associate Professor Atsushi Shirane.