低散射等剖面机身影区后向绕射机理分析

THE MECHANISM ANALYSIS FOR THE BACKWARD DIFFRACTION ON SHADOW AREA OF EQUAL-SECTION FUSELAGE HAVING LOW RADAR CROSS SECTION

阴影区的后向绕射是低散射截面飞行器和部件ＲＣＳ的主要贡献之一，有效地抑制它可以进一步地减缩ＲＣＳ。针对低散射等剖面机身，应用几何绕射理论和等效电磁流法，分析了阴影区的凸曲面爬行绕射和尖劈绕射机理，提出了阴影区后向绕射的ＲＣＳ计算方法，给出了计算实例。通过实验验证，表明提出的分析方法对一般低散射截面机身是有相当精度的。

The backward diffraction on the shadow area of aircraft and its components having low radar-cross-section(RCS)is one of the main contributions of their RCS.If the backward diffraction is curbed effeetively,the RCS can forther be redueed.With the aid of geometric diffraction theory and equivalent electromagnetic current method,the mechanism of camber and edge diffraction on the shadow area for equal-section low-RCS fu selage is analyzed,a method to calculate the RCS of the backward diffraction is proposed,and examples of numerical analysis are given.Through experiments,it is proved that the analysis method proposed is appropriate for the vast majority of the equal-scction low-RCS fuselage.