棱边散射消除特性在目标隐身中的研究

Research on Elimination of Edge Scattering Characteristics in the Field of Target Stealth

摘要:

常见的散射源有镜面反射、棱边散射、行波回波、爬行波回波、尖顶绕射、表面轮廓不连续等，不同类型的散射源对散射体的雷达散射截面有不同的贡献，散射的消除对于目标的隐身具有重要的实际意义。棱边散射是目标隐身中仅次于镜面反射的雷达散射截面(Radar cross section, RCS)强散射源，目前消除棱边散射的措施主要是涂覆吸波材料和将棱边设计成锯齿形，但这两种手段消除棱边散射的效果均不够理想，在一定程度上影响了目标的隐身能力。在棱边上加载渐变阻可以有效地缩减棱边散射，但是渐变阻值电阻片加工困难，而且阻值变化范围有限，限制了其在目标隐身领域中的实际应用。在研究渐变阻值电阻片对棱边散射的缩减效果并确定其阻值分布的基础上，采用在棱边上加载渐变图案电阻片的方式，根据传输线理论，利用CST电磁波仿真软件计算反射系数，通过指数拟合建立渐变图案电阻片与渐变阻值电阻片的对应关系。结果表明，相对棱边加载渐变图案电阻片后，阻值变化范围明显增加，达到大幅消除棱边散射目的，使目标达到良好的隐身效果。通过合理的阻值和图案设计，加载渐变图案电阻片可以在1—18 GHz超宽频范围内实现RCS整体降低95%以上，从而大幅度地缩减棱边散射，进一步提高目标的隐身能力。

Abstract:

Common scattering sources include specular reflection， edge scattering， traveling wave echo， crawling wave echo， tip diffraction and discontinuous surface profiles. Different types of scattering sources contribute differently to radar cross section（RCS） of scatterers. Eliminating scattering sources holds significant practical importance for target stealth. Edge scattering is the scattering source of radar cross section which is next to specular reflection in the field of target stealth. Current mitigation measures， such as coating absorbing materials or designing serrated edges， exhibit suboptimal performance， compromising stealth capability. Loading edges with graded patterned resistive sheets effectively reduces edge scattering. However， graded resistance value resistive sheets face challenges in fabrication and limited resistance variation， restricting their practical stealth applications. This study investigates the reduction effect of graded resistance value resistive sheets on edge scattering， determines resistance distribution patterns， and employs graded patterned resistive sheets to optimize edge loading. According to transmission line theory， reflection coefficient was computed by CST electromagnetic wave simulation software and exponentially fitted to establish correlations between graded patterned resistive sheets and graded resistance value sheets. Through analysis， compared to loading graded resistance value sheets， loading graded patterned resistive sheets significantly expands the operable resistance variation range， thereby achieving significantly mitigation of edge scattering and enabling excellent stealth performance. The results demonstrate that， through rational resistance matching and pattern optimization， the graded patterned resistive sheets achieve an overall RCS reduction exceeding 95% across the ultra-wideband 1—18 GHz range， effectively suppressing edge scattering while further enhancing target stealth.