基于组合梯度超表面的低RCS微带天线设计

针对微带天线的带内和带外雷达散射截面（radar cross section，RCS）减缩问题，提出了一种加载组合梯度超表面的低RCS天线设计方法，以解决传统RCS减缩技术存在的带宽受限和设计复杂问题.该方法将8个梯度方向间隔45°的梯度超单元依次排列在辐射贴片的周围，由于梯度超单元的奇异反射特性，散射场将会被重新分布至各个方向，表现出漫反射效果，从而实现单站和双站的RCS减缩.仿真和测试结果表明:加载组合梯度超表面前后微带天线的RCS在7.2~18.4 GHz减缩了5 dB以上，且微带天线原有的辐射特性基本保持不变.该设计方法具有设计简单、超宽带工作的特点.

Design of low RCS microstrip antenna based on combinatorial gradient metasurface

In regard of in-band and out-band radar cross section(RCS) reduction of microstrip antenna, a method for designing low RCS antenna based on combinatorial gradient metasurface is proposed, which can release the issue about bandwidth limited and design complexity of the conventional technology. The low RCS microstrip antenna is designed by distributing eight kinds of gradient supercells around radiation patch, the supercells have different gradient directions with an interval of 45°. Due to the anomalous reflection property of the gradient supercell, the scattered field is redistributed into various directions and performs like diffusion phenomenon. Therefore, both monostatic RCS and bistatic RCS can be suppressed. The simulated and measured results show that the RCS is reduced by more than 5 dB within 7.2-18.4 GHz as well as the radiation performance was maintained after loading the combinatorial gradient metasurfaces. The design approach features properties such as design convenience and ultra-wideband operation.