镀银织物双层叠放模式与电磁屏蔽效能增量研究

电磁辐射是四大环境污染之一，通过不同电磁屏蔽体的叠加组合能够有效提高屏蔽效能。研究了镀银织物以紧密叠放、夹空气层和夹角叠放3种模式构造，采用小窗法屏蔽效能测试系统实测了0～18 GHz宽频段内双层织物的电磁屏蔽效能的增量问题。结果表明：镀银织物双层紧密叠加有利于电磁屏蔽效能提升，其屏蔽效能可达70 dB,明显高于单层织物，紧密叠放更有利于双层织物的屏蔽效能；夹空气层双层织物在0～6.5 GHz频段的屏蔽效能有所提高，而在其他频段其屏蔽效能呈下降趋势，尤其不利于高频电磁波的屏蔽；夹角叠放双层织物屏蔽效能均达到60 dB以上，大夹角叠放(90°)时使双层织物的屏蔽效能降低。建立了双层织物电磁屏蔽效能的增量模型，为电磁屏蔽效能分析提供了一个新的视角，通过结构优化方式探索屏蔽体构造的最佳配置，对电磁屏蔽体的设计、生产及使用具有一定的参考价值。

Double-layer fabric stacking mode and electromagnetic shielding efficiency increment of silver-coated fabric

Electromagnetic radiation is one of four major environmental pollutions. The superposition and combination of different electromagnetic shielding bodies can effectively improve the shielding efficiency. Three stacking modes of silver-coated fabrics were studied including compact superposition, stacked with air layer, and stacked at a cross angle. The increment of electromagnetic shielding efficiency of double-layer fabrics in the broadband range of 0~18 GHz was measured by the small window method shielding efficiency test system. Results show that the compact superposition of double layers of silver-coated fabric was conducive to the improvement of electromagnetic shielding efficiency. The shielding efficiency could reach up to 70 dB, which was significantly higher than that of single-layer fabric, indicating that compact stacking is more beneficial to the shielding efficiency of double-layer fabric. The double-layer fabric with air interlayer was advantageous to improving the shielding efficiency within the frequency band of 0~6.5 GHz, while the shielding efficiency showed a downward trend in other frequency bands, and it was especially unfavorable for the shielding of high-frequency electromagnetic wave. The shielding efficiency of double-layer fabrics stacked at a cross angle was more than 60 dB. When stacked at a large cross angle (90°), the shielding efficiency of double-layer fabrics was reduced. The incremental model of electromagnetic shielding efficiency of double-layer fabrics was established, which provides a new perspective for the analysis of electromagnetic shielding efficiency. The optimal configuration of shielding structure was explored through structural optimization, which has certain reference value for the design, production, and utilization of electromagnetic shielding.