左手材料涂敷目标的RCS仿真研究

RCS Simulation of Target Coated with Chiral Medium

左手材料的介电常数和磁导率都为负值,电场、磁场和波矢量在左手材料中表现为左手螺旋关系,相速与群速方向相反。根据传输线理论分析了波入射到分层媒质上的表面反射系数,计算了随入射波频率、涂层厚度变化情况下的左、右手材料的反射率;基于非均匀有理B样条参数曲面模拟目标的几何外形,采用物理光学法计算了涂敷左手材料目标的雷达散射截面。结果说明左手材料能明显减少反射波,使目标的RCS大大减缩。

The permittivity and permeability of left-handed material both are negative. When electromagnetic wave is propagating in this medium, the electric field, magnetic field and wave vector conform to the left-hand screw rule. It means that the direction of phase velocity is contrary to the direction of group velocity. The reflection coefficients of multilayered coating are analyzed by transmission line model. And the refleetivity of left-handed material and the reflectivity of right-handed material are computed based on varied frequency of incident wave and varied thickness of coating. Shape of the target is modeled with non-uniform rational B-spline surfaces. And the radar cross section （RCS） of the target coated with left-handed material is calculated by physical optics method. The results show that the reflected wave is reduced by left-handed material. Additionally, the RCS of coated target is decreased obviously.