A joint team led by Professors Wook-Sung Kim and Wonbin Hong in POSTECH's Department of Electrical Engineering, comprising first author Junseok Ma, advised by Kim, Jinyoung Choi, Seongeun Park, Imbo Gong, Daehyeon Kim, Cheonga Lee, Youngno Yoon, and Myeongjin Hwang, published a review of liquid-crystal antenna design trends and future research directions in Advanced Materials, a leading journal in materials and optoelectronics convergence research. The paper was selected as a Frontispiece feature.

As operating frequency increases, all RLGC element characteristics become more frequency-dependent. Tunable inductive and capacitive elements operating above several tens of GHz are extremely rare, with major limitations arising from semiconductor processes, self-resonance frequency, and low Q. Liquid crystals, by contrast, offer low loss at high frequencies, reconfigurability, and competitive cost, making them attractive for next-generation communications systems.

Most liquid-crystal antenna design has focused on optimizing device structures and electrical properties. Proposed RF devices include phased-array antennas, holographic antennas, and reconfigurable intelligent surfaces. More recently, various methods have been proposed to improve response speed, tunability, and loss tangent.

The team presents approaches to exceed existing performance limits and exploit diverse physical and chemical properties of liquid crystals. It emphasizes that liquid-crystal engineering must be optimized alongside antenna design. As the first review of liquid-crystal antenna device design trends from the perspective of liquid-crystal material properties, the paper outlines future design directions and is expected to have a meaningful impact on related research.

The research was supported by the Samsung Science & Technology Foundation.