一种双频超薄吸波结构在微带天线中的应用

Dual-band ultra-thin metamaterial absorber and its application in reducing RCS of the microstrip antenna

设计了一种新型超薄双频带雷达吸波结构,通过提取阻抗参数、分析表面电场和电流分布,阐明了其吸波原理,并将其用于双频带微带天线,减缩天线带内雷达散射截面.结果表明,该结构在两个不同的频段内实现了高效吸波,且吸波效果具有入射角稳定性和极化角不敏感性;加载该吸波结构后,微带天线的辐射性能保持不变,而在天线的工作频率4.29GHz和6.49GHz处,其雷达散射截面分别减缩了8.59dB和9.9dB.实测与仿真结果相吻合,表明该结构能够有效应用于双频带天线的带内隐身.

A novel ultra-thin dual-band metamaterial absorber is designed. Its absorbing mechanism is illuminated by calculating the effective impedance and analyzing the electric fields as well as currents distributions. Then the absorber is applied to the dual-band microstrip antenna to reduce its in-band RCS （Radar Cross Section）. The results show that this absorber achieves high absorption in two frequency bands. Moreover, its absorbing properties are incident angle insensitivity and polarization independence, and when it is loaded to the dual-band microstrip antenna, it can reduce the antenna＇s RCS by 8.59 dB and 9.9 dB at 4.29 GHz and 6.49 GHz, respectively, whieh are the working frequencies of the dual-band antenna. There is a good agreement between simulated and measured results, showing that this absorber can be used for the improvement of the dual-band antenna＇s in-band invisibility of the antenna.