材料科学与工艺  2019, Vol. 27 Issue (3): 23-28  DOI: 10.11951/j.issn.1005-0299.20180088 0

### 引用本文

WEI Lintao, HUANG Daqing, ZHOU Zhuohui, CHENG Hongfei, ZHAO Yi. Radar absorbing properties of meta-materials with low electric conductivity[J]. Materials Science and Technology, 2019, 27(3): 23-28. DOI: 10.11951/j.issn.1005-0299.20180088.

### 文章历史

Radar absorbing properties of meta-materials with low electric conductivity
WEI Lintao , HUANG Daqing , ZHOU Zhuohui , CHENG Hongfei , ZHAO Yi
Stealth Materials and Coating Lab, Beijing Institute of Aeronautical Materials, Beijing 100095, China
Abstract: The absorbing properties of meta-materials prepared by low electric conductivity materials are studied in this paper. The simulation method was adopted to calculate the absorbing properties of meta-materials with different electric conductive rates, and the corresponding principle was studied. A meta-material structure with a conductivity of 2.3×104 S/M was processed through spray coating on the composite substrate. The radar absorbing properties of absorbers at different substrate thicknesses were investigated. Simulation results indicate that meta-materials with low electric conductivity can realize deep and wide absorption on electrical magnetic wave and the optimal thickness value of the substrate can be obtained, suggesting that conductivity can be another parameter for the design of meta-materials. When the thickness of the prepared meta-material substrate was 2 mm, a deep absorption of -23.2 dB was achieved at 7.8 GHz, and the experimental principle was in accordance with simulation results. The spraying method can be expected to solve the problem of meta-materials application in areas with large curvature, complex shapes, and so on, which opens up a new direction of meta-materials design and fabrication in large scale.
Keywords: low electric conductivity    meta-materials    conductive silver paste    radar absorbing material    spraying method

1 设计超材料结构

 图 1 超材料结构设计(a)、电磁波入射方向(b)及吸波性能仿真结果(c) Fig.1 Design of meta-materials (a), electromagnetic wave incidence direction (b), and the simulation result of meta-materials radar absorbing (c)
 图 2 不同电导率超材料的吸波性能仿真结果 Fig.2 Simulation results of meta-materials with different conductive rates

 图 3 不同基底材料厚度吸波性能仿真结果 Fig.3 Simulation results of the substrate with different thicknesses

 图 4 电导率为103 S/m时电磁场能量分布 Fig.4 Energy distribution when the conductive rate is 103 s/m: (a) electric energy; (b) magnetic energy; (c) metal back plate magnetic energy

 图 5 电导率为106 S/m时电磁场能量分布 Fig.5 Energy distribution when the conductive rate is 106 s/m: (a) electric energy; (b) magnetic energy; (c) metal back plate magnetic energy
2 实验验证

 图 6 喷涂模具 Fig.6 Spraying mould

 图 7 实物图E玻璃复合材料板 Fig.7 E-glass composite material

 图 8 1 mm E玻璃基板超材料实验结果 Fig.8 Experiment result of meta-materials with 1 mm E-glass substrate
 图 9 不同基底材料厚度下的实验结果 Fig.9 Experiment results based on different substrate materials

3 结论

1) 在低电导率条件下，增加基底材料厚度可以实现宽频深吸收，并且厚度有最优值，这就说明电导率也是设计超材料吸波性能的关键参数之一.

2) 根据仿真结果，采用优异的导电涂料制备了超材料结构，超材料结构的吸波性能与仿真结果的基本结论吻合.

3) 吸收频带的移动是由于基底材料电性能以及超材料电导率与仿真设置不同所引起的，实验结果的基本规律与仿真结果一致.

4) 喷涂法制备低电导率超材料吸波体，为超材料的大规模应用开辟了新的方向.