摘要
本文论证氮化硼天线窗的再入信号衰减取决于其表面电导;表面电导又正比于其介电损耗角正切。它们都与再入时烧蚀表面温度的平方成正比,与平行于透射方向的温度分布梯度成反比。BN/SiO_2复合,可降低其烧蚀表面温度,增大其沿透射方向的温度梯度,从而改善其高温介电性能。BN与SiO_2复合是减小氮化硼天线窗再入信号衰减的行之有效的方法。
It is Proved that the electromagnetic signal attenuation thro-ugh the BN antenna Window during the reentry depends on its surfaceconductivity which have direct relationship to tgδ. All of them are directlyproportional to the square of the reentry ablation surface temperature (T_F)of the window and are inversely proportional to the temperature gradient(T_G) along the heat conductive direction. To compound BN and SiO_2 candecrease its T_F, increase its T_G, improve its high temperature dielectriccharacteristics, and therefore is an effective approach to reduce the reentrysignal attenuation of BN antenna window.
出处
《宇航材料工艺》
CAS
CSCD
北大核心
1993年第2期17-21,共5页
Aerospace Materials & Technology
