双层微纳结构增强电磁屏蔽的机理分析与验证

Mechanism analysis and verification of double-layer micro-nano structure to enhance electromagnetic shielding

为了实现对双层微纳结构增强电磁屏蔽的机理分析,建立了分析模型并进行了理论公式推导。以方格结构为例,分析了双层微纳结构增强电磁屏蔽效能的机理,推导出双层微纳结构电磁屏蔽的理论计算公式,理论计算与电磁仿真软件CST Microwave Studio全波仿真结果吻合较好。在全波仿真中微纳结构比计算对应波长小2~3个数量级,这验证了机理分析和全波仿真软件计算的正确性。所提供的电磁屏蔽增强机理分析及计算公式可扩展到多层微纳结构,具有通用性。为进一步验证机理分析和全波软件仿真结果的正确性,制备了双层方格微纳结构样件,样件的实测结果与理论和全波仿真结果基本一致,在2~18 GHz内屏蔽效能大于45 dB,平均透光率超过了71%,具有良好的透明屏蔽性能。这一机理分析为高透光和高效电磁屏蔽微纳结构设计提供了理论指导。

An analysis model is established and a theoretical formula is deduced to analyze the electromagnetic shielding enhanced by a double-layer micro-nano structure. By using the square structure as an example,the effectiveness of the electromagnetic shielding enhanced by the double-layer micro-nano structure is investigated,and a calculation formula for the electromagnetic shielding of the double-layer structure is derived. In addition,a full-wave simulation is carried out using CST Microwave Studio,the results of which are in good agreement with those of the theoretical calculations. In the full-wave simulation,the micro-nano structure is two-three orders of magnitude smaller than the calculated corresponding wavelength,which verifies the correctness of the mechanism analysis and the calculation of the full-wave simulation software.The analysis of the electromagnetic shielding enhancement mechanism and the provided calculation formula can be extended to the multilayer micro-nano structure,which is universal. To further verify the accuracy of the mechanism analysis and the full-wave software simulation results,a square double-layer micro-nano structure sample is prepared. The measured results of the sample are essentially consistent with the theoretical and full-wave simulation results. The shielding effectiveness is greater than 45 dB in the range of 2-18 GHz,and the average light transmittance exceeds 71%,which has good transparent shielding performance. This mechanism analysis provides theoretical guidance for designing micro-nano structures with increased light transmission and high-efficiency electromagnetic shielding performance.