摘要: |
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104GHz;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22GHz附近的吸收峰可达-203dB. |
关键词: 石膏 蜂窝结构 吸波材料 反射率 |
DOI:103969/j.issn1007 9629201601032 |
分类号: |
基金项目:“十二五”国家科技支撑计划项目(2014BAB15B02 02) |
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Microwave Absorbing Properties of Honeycomb Structure Filled with Gypsum |
JI Zhijiang, XIE Shuai, YANG Yang, HOU Guoyan, WANG Jing
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State Key Laboratory of Green Building Materials,China Building Materials Academy, Beijing 100024, China
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Abstract: |
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 218GHz were studied using N5234A PNA 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 -10dB in the whole range of 818GHz when the side length and the height are 6mm and 8mm, 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 218GHz and the lowest peak value could reach -203dB. |
Key words: gypsum honeycomb structure microwave absorbing material reflectivity |