Frequency Selective Surface towards 6G Communication Systems: A Contemporary Survey

Frequency selective surfaces (FSSs) have attracted extensive attention for suppressing interference and improving channel quality and coverage by selectively transmitting or directionally reflecting electromagnetic waves in a specific frequency range in wireless communication networks. Therefore, FSS technology is considered to be another candidate after intelligent reflective surfaces (IRSs) in the sixth generation (6G) communication systems. In this paper, we provide a comprehensive investigation of the theory, design, and classification of FSS, and a contemporary overview of its vision and current applications in future 6G networks, as well as some emerging use cases of FSSs in 6G networks. Then, we describe the fundamentals and design methods of FSS from architecture, performance metrics, and experimental analysis methods and classify the relevant papers according to the FSS applications. Moreover, we review systematically the frequency selection characteristics, reflection, transmission, and absorption properties of FSS, and discuss the corresponding communication models. Additionally, we provide an overview of the vision and requirements for FSS-assisted 6G networks and summarize the FSS communication architecture and performance analysis towards 6G networks. Since the IRS technology is another metasurface candidate for 6G networks, we compare and review them with those for IRS-assisted 6G networks. Furthermore, we review some emerging use cases in 6G networks and present a new use case of adaptive spectrum allocation based on FSS. Finally, based on an extensive literature review and common weaknesses of FSS extant literature, we offer several challenges and some potential research directions.