基于吸波超材料的微带天线设计

为缩减天线带内雷达散射截面,设计出一种频带较宽的超材料吸波体。该吸波体是由两层金属及其中间的有耗介质组成,上层金属是由刻蚀四个不同大小方孔的贴片形成的电谐振器,下层金属不刻蚀,作为整个金属地板。通过优化结构参数,得到了一种极化不敏感、宽入射角的超薄吸波体,吸波率达到97%,厚度只有0.3mm。仿真结果表明:通过渐变开孔,该吸波体吸波带宽大大扩展。相比普通微带天线,加载该吸波体后天线在工作频带内法向RCS减缩可达3~12.6dB,同时天线的增益也有较大提高。

Design of microstrip antenna based on absorbing metamaterial

In order to reduce the radar cross section of antenna, a wideband-enhanced metamaterial absorber is designed. The absorber is composed of two metallic layers by a lossy dielectric spacer. The top layer consists of etched four different square hole in a periodic pattern and the bottom one is a solid metal. By fine adjusting geometry parameters of the structure, a polarization-insensitive, wide-incident-angle ultra-thin absorber is obtained, that has an absorption of 97~ and a thickness of only 0.3ram. The simulated result shows that through the gradual opening, the absorbing bandwidth of metaraaterial absorber greatly expands. Compared with the conventional microstrip antenna, the proposed antenna has an RCS reduction of more than 3dB in the boresight direction in the working frequency band, and the largest reduction can reach 12. 6dB. Simultaneously, it can increase the gain highly.