低反射高吸收梯度电磁波屏蔽复合材料研究

Study on shielding functionally gradient materials with low reflection loss and high absorption loss for electromagnetic wave

为了减少反射回空间的电磁波对电磁环境造成的二次污染,本文提出了双梯度电磁屏蔽材料SFGM(shieldingfunc tionallygradientmaterials)设计的构想,来实现对频率<1GHz的电磁波的低反射高吸收。制备的镍/镍锌铁氧体/环氧树脂梯度电磁屏蔽材料,其结果表明:在频率<1GHz时,双梯度材料对电磁波的反射损耗比非梯度材料平均降低了6～8dB;而吸收损耗平均提高了6～14dB。在中心吸收层的衰减常数不变时,对电磁波的吸收损耗随吸收层厚度增加而增加。

In order to reduce the pollution, which the electromagnetic wave being reflected back into air will pollute again the electromagnetic environment, in this paper, the double gradient model for shielding functionally gradient materials (SFGM) was put forward to realize low reflection loss and high absorption loss for electromagnetic wave. The gradient composite shielding coatings based on nickle and NiZnFe_2O_4 were prepared. The results showed the reflection loss of the gradient coatings was decreased by 6～8dB and the absorption loss of the gradient coatings was increased by 6～14dB than that of the non-gradient coatings in less than 1GHz. When the attenuation constant of the absorption layer in center did not change, the absorption loss increased with the thickness of the absorption layer.