Professor Lee Hojin's Team at Soongsil University Develops Ultra-Compact Wireless Power System

Increased Practical Usability for Wearable Devices

Soongsil University announced on June 5 that the research team led by Professor Lee Hojin of the Department of Electronic and Information Engineering has developed an ultra-compact wireless power transfer system based on energy-focusing metasurfaces, applicable to unmanned mobile devices.

The research team consists of Professor Lee Hojin (corresponding author), Dr. Lee Wonwoo (Department of Electronic and Information Engineering, first author), Dr. Park Hongsu (Department of Intelligent Semiconductor Engineering, co-first author), Professor Park Changgeun (Department of Electronic and Information Engineering), and Professor Hong Sunki. The newly developed metalens enables electromagnetic energy focusing using a single-layer metasurface less than 1 mm thick. It demonstrated excellent focusing performance not only for vertically incident waves but also for electromagnetic waves with various angles of incidence.

Existing lens technologies based on metasurfaces have mostly focused on the visible light spectrum, making it difficult to apply them to communications and antenna applications utilizing the millimeter-wave band.

The Soongsil University research team has presented a new metasurface lens design technology that operates independently of polarization direction at the central operating frequency of 22.5 GHz, thereby enabling electromagnetic focusing in the millimeter-wave band. This metalens exhibits low sensitivity to the angle of incidence, so the focal point remains stable even when electromagnetic waves are incident at tilted angles between -10 and 10 degrees.

The electromagnetic energy focused by this metalens is converted into direct current voltage via a CMOS-based ultra-compact rectifier after passing through a patch antenna. It is then further converted to the voltage required to drive ultra-compact unmanned mobile devices through a DAC converter. Through this process, the research team has established an ultra-compact wireless power transfer system that integrates metalens and CMOS circuit technologies.

Professor Lee Hojin stated, "This research is the first case of implementing a wireless power transfer system by integrating electromagnetic focusing metasurface technology with CMOS circuit design technology. In the future, we plan to develop systems capable of broadband and wide-angle electromagnetic focusing and higher-efficiency power conversion, followed by further research to verify their commercial viability."

This content was produced with the assistance of AI translation services.