Recent Developments of Transmissive Reconfigurable Intelligent Surfaces:A Review

摘要

Reconfigurable intelligent surface(RIS)is considered as one of the key technologies for the next-generation mobile communication systems.The transmissive RIS is able to achieve dynamic beamforming capability while transmitting an in-band RF signal through its aper-ture,and has promising prospects in various practical application scenarios.This paper reviews some of the latest developments of the trans-missive RIS.The approaches for transmissive RIS designs are classified and described briefly.Numerous designs with different phase resolu-tions,such as 1-bit,2-bit or continuous 360°phase shifts,are presented,with detailed discussions on their operating mechanisms and trans-mission performances.The design solutions for various transmissive RIS elements are summarized and compared.