冲击电压下方形谐振环频率选择超材料蒙皮的沿面放电长度影响因素研究

Analysis of Factors Affecting the Length of Surface Discharge on Skins of Square Ring Resonator Frequency Selective Metamaterial Under Impulse Voltage

频率选择超材料是极具前景的先进雷达罩材料,然而其雷电屏蔽失效率较高,工程化应用受到限制。选择最优的分流条间距是保障超材料电磁传输效率和雷电屏蔽成功率的关键,冲击电压下超材料蒙皮的沿面放电长度是决定分流条最优间距的因素之一。基于实际雷达罩结构,设计并搭建了针对方形谐振环频率选择超材料进行蒙皮沿面放电的试验模型,研究超材料接地水平间距、蒙皮放电次数、蒙皮材质对蒙皮沿面放电长度的影响,观察了放电后蒙皮表面的损伤部位微观形貌,测量了蒙皮表面电阻率以及蒙皮表面电荷分布情况,并基于上述观察和测量结果,对蒙皮表面放电的试验结果进行了分析。结果表明:超材料接地水平间距的变化对玻纤/环氧树脂蒙皮沿面放电长度影响较小;随着蒙皮放电次数的增加,玻纤/环氧树脂蒙皮沿面放电长度逐渐增加;蒙皮表面电阻率对沿面放电长度有显著影响,表面电阻率与介电常数乘积较小的蒙皮显示较大的沿面放电长度。研究结果可以为超材料雷达罩的雷电防护提供参考。

Frequency selective metamaterials are promising advanced radome materials.Lightning shielding failure rate of this kind of metamaterial is high,which restricts its engineering application.Choosing the optimal distance between the lightning diverter strips is the key to guarantee the metamaterial electromagnetic transmission efficiency and the success rate of lightning shielding.The length of surface discharge on the skin under the impulse voltage is one of the factors determining the optimal distance between the strips.Based on the actual radome structure,this paper designed a test platform for discharge along the square ring resonator frequency selective metamaterial skin surface.The influences of grounding position,discharge times and skin material on the length of surface discharge(horizontal direction)on the skin were studied.The micro damage morphology of the skin along the surface was observed after discharge.The surface resistivity and the charge distribution on skin surface were measured.Based on the above observation and measurement results,the test results of surface discharge on the skin were analyzed.Results show that,the influence of grounding position on the length of surface discharge on the glass fiber reinforced epoxy resin skin is small.With the increase of discharge times,the length of surface discharge on the skin grows.The surface resistivity influences the length of surface discharge obviously,with the decrease of product of surface resistivity and dielectric constant,the length of surface discharge increases.It is hopedthat research results could provide theoretical reference for lightning protection on metamaterial radomes.