报告摘要

Intelligent Reflecting surface (IRS) technology for 5G communications, which electrically controls the direction of reflection, has been attracting attention in recent years. Among the IRS using diodes or MEMS are being researched as a typical phase control technology for realizing IRS, the liquid crystal-based IRS (LC-IRS)is also expected for 5G and 6G communications based on the liquid crystal display technology. The phase is changed by controlling the dielectric constant of LCs to actively scanning the direction of the reflected beam. When a voltage is applied to the liquid crystal, permittivity of the liquid crystal slightly changes (typically 2.5 - 3), and this change is used to change the effective length of each reflectarray elements and to change the reflection phase. Although the LC-IRS has the advantage of being able to achieve continuous phase, which is difcult to achieve with 1-bit or 2-bit reflect arrays, it has the disadvantage that the magnitude of the reflection coeficient also changes. In this paper, we propose a method to reduce the change of the reflection magnitude by lowering the Q-value of the resonance of printed dipoles. Also a scattering pattern with low sidelobes is demonstrated by the array factor analysis.

个人简介

Hiroyasu Sato (Member, IEEE)received the D.E. degree from Tohoku University, Sendai, Japan, in 1998. He is currently an Assistant Professor with the Department of Communications Engineering, Tohoku University. His current research interests include the experimental study of electromagnetic waves, computational electromagnetics, antennas in plasma, antennas for plasma production, broadband antennas, wireless power transfer, and active/passive millimeter-wave imaging, and Liquid Chrystal based Intelligent Reflecting Surface (IRS). Dr. Sato is a member of the Institute of Electronics, Information and Communication Engineers (IEICE). He received the First Place of the BestPaper Award from the International Symposium on Antennas and Propagation (ISAP) in 2017. He received lEICE Communications Society ComEX Best Letter Award in 2023. Also he was nominated for the Best Paper Award in ISAP 2024.