飞行器表面缝隙电磁散射特性研究

 在常规飞行器的各类电磁散射源中，缝隙属于弱散射源，但对于隐身飞行器，缝隙电磁散射不可忽略。为研究飞行器缝隙电磁散射特性，在不同极化下，将缝隙置于金属平板的对角线，削弱金属边缘电磁散射影响。通过系列雷达散射截面(RCS)测试分析，得到了缝隙电磁散射随缝隙宽度、（多缝隙）缝隙间距的变化规律，以及其极化特性。不同宽度单缝测试结果表明:对于水平极化，缝隙宽度小于波长的1/4时，缝隙的宽度增加将导致缝隙引起的表面波散射快速增长，反之，呈下降趋势；对于垂直极化，缝隙宽度较小时试件的电磁散射与无缝金属平板接近，当缝隙宽度大于波长的1/2时，宽度增加时，其散射增强。多缝隙测试结果表明缝隙间距会影响散射的空间分布、波峰位置，可以理解为对各单缝隙散射叠加效果的影响。垂直极化影响强于水平极化。

Research on Electromagnetic Scattering Characteristics of Slits on Aircraft

Slits are feeble sources among the various electromagnetic scattering sources on a traditional aircraft.But for the stealth military aircraft,scattering contribution of slits is remarkable since the main sources are heavily reduced.To analyze the scattering characteristics of slits at different polarizations,a slit was placed in the diagonal of a metal plate to weaken the influence of metal edges and the diagonal was placed from vertical to horizontal.By means of a series of rodar cross section(RCS) testing,the polarization rules,width parameter influence,interval parameter influence,and other characteristics of slits are investigated.Experiments with different slit widths demonstrate two points: for HH polarization,when the slit width was less than a quarter of the wavelength,increase in slit width would considerably enhance the surface wave effect,but when it was greater than a quarter of the wavelength,its increase tended to reduce scattering;for VV polarization,the scattering of the test piece was close to a plate with no slit when the slit width was small and scattering was enhanced when the slit width was greater than half of the wavelength.Experiments with multi-slits show that interval parameters would have an impact on the RCS distribution and peak location by coupling the effect of individual slits.The influence of VV polarization was greater than HH polarization.