一种宽带吸波超材料在天线RCS缩减中的应用

A Broadband Absorbing Metamaterial Applied to the RCS Reduction of the Patch Antenna

本文设计了一种由圆环和带电阻方环周期排列构成的宽带吸波超材料,并将其用于贴片天线雷达散射截面(RCS)的缩减.吸波单元由一个带电阻的方环和4个环绕在方环顶角周围的1/4圆弧构成.10×10单元构成的吸波超材料在6.5 GHz~12.5 GHz(相对带宽为63%)频带内的吸波率均在90%以上,吸收峰值可达98%.本文设计的低RCS天线是将此10×10单元的吸波超材料中心的2×2个单元去掉,形成一个矩形窗口,并将贴片天线置于矩形窗内.仿真和测试结果表明:所设计天线在9.3 GHz~10.1 GHz工作频带内的RCS平均缩减8.1 dB,在6 GHz~12 GHz频率范围内平均缩减10.2 dB,RCS的缩减量在7.68 GHz处达到最大值23.54 dB,并且辐射方向性得到明显改善.

In this letter,a broadband absorbing metamaterial composed of periodic circular loops and square loops with resistances is designed and applied in the radar cross section(RCS)reduction of a patch antenna.An absorbing unit is composed of four quarter circular loops and a square loop with four lumped resistances.The absorptivity of the absorbing metamaterial composed of 10×10 units is over 90%in the frequency range of 6.5 GHz~12.5 GHz,with a peak value of 98%.A 2×2 units window is opened in the middle of the proposed absorbing metamaterial,and the patch antenna is embedded in the window.The simulated and measured results show that the average RCS of the proposed antenna is reduced by 8.1 dB in the operating band of 9.3 GHz~10.1 GHz,10.2 dB in the range of 6 GHz~12 GHz,and the maximum RCS reduction is 23.54 dB at 7.68 GHz.The radiation directivity of the proposed antenna is significantly improved.