A Bandpass Frequency Selective Surface With High Selectivity

In this paper, a five-layer cascaded dual-polarized broadband bandpass frequency selective surface structure is designed and analyzed. The structure is arranged in equilateral triangles, and the top and bottom metal layers are composed of two metal concentric rings combined with a cross-finger structure; the middle three metal layers are composed of two hexagonal patches and a hexagonal ring coupling. The CST simulation results show that the transmission passband of this structure with a transmission loss higher than -1dB covers 8.1-11.76 GHz, and the highest transmission loss in the passband is 0.73dB, and the incidence angle ranges from -45° to 45°, and the 3db rectangularity coefficient is 0.85. The designed FSS structure achieves a broadband bandpass with a frequency selectivity factor of 0.85. The maximum transmission loss in the passband is 0.73 dB, the incidence angle ranges from -45° to 45°, and the 3 dB rectangularity coefficient is 0.85. The designed FSS structure achieves good polarization stability, angular stability, and out-of-band cutoff.