石膏填充蜂窝结构吸波材料的吸波性能

Microwave Absorbing Properties of Honeycomb Structure Filled with Gypsum

通过在浸渍乙炔炭黑的蜂窝结构中填充石膏,制备了具有蜂窝结构的石膏基吸波材料,采用弓形反射法研究了该吸波材料在2～18GHz的吸波性能.结果表明：蜂窝结构的孔格边长和高度对材料的吸波性能有一定影响;当石膏填充单层蜂窝结构吸波材料在2～18GHz频宽,蜂窝结构孔格边长为6mm,高度为8mm时,反射率低于-10dB的吸收频宽为10.4GHz;石膏填充双层蜂窝结构吸波材料,由于匹配层和吸收层形成了阻抗梯度结构,在一定程度上改善了其吸波性能,故能够在2～18GHz频宽内获得小于-8dB的吸波效率,反射率曲线存在5个吸收峰,在2.2GHz附近的吸收峰可达-20.3dB.

Honeycomb paperboards after dipping in acetylene carbon black were introduced to gypsum based microwave absorbing materials.Gypsum boards with single-layer and double-layer honeycomb structure were prepared and the microwave absorbing properties in the range of 2-18 GHz were studied using N5234APNA-L microwave network analyzer.The results indicate that microwave absorbing properties of the specimens with single-layer honeycomb structure are mainly affected by the size of each unit cell,including the side length and the height.The reflection loss of the gypsum board is below-10 dB in the whole range of 8-18 GHz when the side length and the height are 6 mm and 8 mm,respectively.For gypsum boards with double-layer honeycomb structure,the microwave absorbing property is further improved due to the impedance gradient structure formed by different layers,including matching layer and absorbing layer.Different unit cell sizes are designed for two layers based on the impedance match principle.The optimal reflection loss obtained in the double-layer gypsum boards is below-8dB in the frequency range of 2-18 GHz and the lowest peak value could reach-20.3dB.