双波段频率选择表面复合材料的性能研究

Study on Properties of Dual-band Frequency Selective Surface Composites

以三阶正十字分行贴片旋转45°得到的图形为基本周期单元,设计了一种新型周期图案的频率选择表面(FSS)。将FSS和聚甲基丙烯酰亚胺泡沫复合制备得到双波段频选复合材料,通过对频率选择表面尺寸和泡沫厚度的设计,研究了其在1~18GHz内的电磁波插损。研究结果表明,当FSS厚为12μm,边界宽为30μm,两侧泡沫厚为5mm时,双波段频率选择超材料在特定的频段内电磁波插损的实验值和仿真值基本一致,即在2.5~3.5GHz及8.5~11GHz频段内,90%频点插损值小于0.9dB;随着电磁波入射角的偏移,带内插损值增大,有效带宽减小。

A kind of frequency selective surface（FSS）with a new periodic pattern has been designed by using the pattern obtained by rotating the third-order straight cross branch patch into 45°as a basic periodic unit.The dualband frequency selective composite material has been prepared with compounding of FSS and the polymethyl acrylamide foam.The electromagnetic wave insertion loss in the range of 1 GHz to 18 GHz has been studied by designing the frequency selection surface size and foam thickness.The results show that the experimental value and the simulation value of the electromagnetic wave insertion loss of this dual-band frequency selective composite material in a specific frequency range are almost the same when the thickness of FSS is 12μm,the boundary width is 30μm and the thickness of foam on both sides is 5 mm.That is,the insertion losses of frequency points of 90% are all less than 0.9 dB in the range of 2.5-3.5 GHz and 8.5-11 GHz.As the incident angle of the electromagnetic wave offsets,and the in-band insert loss increases,the effective bandwidth reduces.