基于十字形结构的相位梯度超表面设计与雷达散射截面缩减验证∗

摘要

基于十字形结构设计了一种在雷达波低频段极化不敏感的相位梯度超表面,并通过仿真和实验进行了验证.不同金属十字周期结构单元复合,在超表面上形成附加的平行波矢分量,对反射波波前进行调控,获得超表面后向雷达散射截面积(RCS)缩减.在设计波段内,超表面在法线方向的单站RCS缩减达18.19 dB,偏离法线−30◦—+30◦范围的单站RCS平均缩减达8 dB；仿真与实验结果符合较好.%A two-dimensional phase gradient meta-surface based on cross structure insensitive to polarization is designed and verified by simulation and experiment. Several periodic metal cross structures are integrated into a superstructure, and an additional component of the wave vector on the meta-surface is formed and the direction of refelction wave can be regulated. Thus the backward radar cross section (RCS) reduction can be realized by the mechanism of anomalous reflection. Experimental results indicate that in a frequency range from 3.2 to 3.4 GHz, the reduction of backward RCS of meta-surface reaches a highest value of 18.19 dB in the normal direction of meta-surface and 8 dB on the average in an angular range between−30◦ and+30◦.