Synthesis Design of Bandpass Frequency Selective Surface With Flat In-Band Group Delay Response

作者：Jiawei Xu, Fu‐Chang Chen, Kai‐Ran Xiang · 发表于：IEEE Antennas and Wireless Propagation Letters · 年份：2025 · DOI：10.1109/lawp.2025.3626035 · 被引用次数：2 · 研究领域：Advanced Antenna and Metasurface Technologies、Metamaterials and Metasurfaces Applications、Full-Duplex Wireless Communications

This letter proposes a novel design of frequency selective surface (FSS) based on patch resonators, which serves not only as a bandpass filter but also as a group delay equalizer. The FSS exhibits fourth-order bandpass filtering characteristics with a center frequency of 5 GHz and a fractional bandwidth of 19.4% in measurement. The application of cascaded quadruplet (CQ) topology brings in cross coupling, which generates a complex symmetric transmission zero pair (CS-TZP). Consequently, the group delay response is agilely controllable by manipulating the CS-TZP. For validation, a prototype is fabricated and measured. The measured results are in good accordance with the simulation for both frequency and group delay responses. The proposed FSS has a flat in-band group delay response with a maximum fluctuation of only 0.26 ns in full-wave simulation and 0.28 ns in measurement.