Ji-hwan Lee, a PhD student in POSTECH’s Department of Electrical Engineering (advisor: Professor Wonbin Hong), received the President’s Award of the Korea Communications Agency (KCA) at the 24th Radio Science Paper Competition, jointly hosted by the Korean Institute of Electromagnetic Engineering and Science and KCA. His paper was titled “Spatially Selective Wave Control through Near-Field Beam Focusing Based on a Holographic Time-Reversal Mirror.”

The paper proposed an inverse antenna design technique based on the time-reversal principle. In particular, it introduced the concept of a holographic time-reversal mirror that uses the time-reversal symmetry of electromagnetic waves to reconstruct the electromagnetic field at a specific location, simultaneously enabling precise focusing, adjustable focal positioning, and interference cancellation in the near field.

The study also experimentally demonstrated that independent electromagnetic channels that do not spatially interfere with one another can achieve both high spatial resolution and interference suppression, even in multiuser environments.

Academically, the work fundamentally clarified the principles of near-field focusing and established a new theoretical framework for near-field beamforming. Industrially, it laid a foundation for applications in next-generation near-field wireless communications, radar sensing, biomedicine, and other fields.

October 2025