The field of reconfigurable intelligent surfaces (RIS) and millimeter-wave (mmWave) communications is rapidly advancing, with a focus on improving energy efficiency, reducing interference, and enhancing signal quality. Recent research has explored the use of RIS in multi-operator wireless communication systems, where spatial correlation and inter-operator interference are significant concerns. Additionally, there is a growing interest in developing active RIS technology, which can amplify signals to combat double-fading effects.

Noteworthy papers in this area include the development of a novel architectural compact two-dimensional resonant MEMS scanning mirror, which achieves high performance and low system complexity. Another significant contribution is the proposal of cognitive radio functionality for STAR-RIS-assisted rate-splitting multiple access systems, which enables adaptive control of transmission and reflection in cognitive radio scenarios.

Furthermore, researchers have investigated the integration of noise modulation with zero-energy RIS, which can harvest energy from interference signals and improve communication performance. The effect of inter-operator interference in multi-RIS communication systems has also been studied, and analytical results have been derived to characterize system performance.

Overall, these advancements have the potential to significantly improve the efficiency and effectiveness of mmWave communication systems, enabling reliable and high-speed data transmission in a variety of applications.

Notable papers: The paper on 2D PZT MEMS resonant scanner presents a novel design for a compact and high-performance scanning mirror. The paper on cognitive radio functionality for STAR-RIS-assisted RSMA networks proposes a new approach to adaptive control of transmission and reflection in cognitive radio scenarios.