论文部分内容阅读
基于超材料的电磁谐振特性,设计、制作了一种极化无关的宽带低雷达散射截面(radar cross section,RCS)超材料吸波体.通过场分布和反演法分析了其吸波机理,利用波导法和空间波法测试了其吸波率和RCS特性.理论分析表明:在平面波的作用下,该吸波体对某一吸波频率在不同的位置分别提供电谐振和磁谐振,对不同的吸波频率,利用不同的介质层提供主要的能量损耗,从而有效减弱了电磁耦合,保证了宽频带的强吸收特性.实验结果表明:设计的三层结构吸波体吸波率达90%以上的带宽是单层结构的4.25倍,RCS减缩10 dB以上的带宽为5.1%,其单元尺寸为0.17λ,厚度仅为0.015λ.该吸波体的低RCS特性还具有极化无关、宽入射角的特点,且通过改变吸波体的夹层结构可以实现工作带宽的灵活调节.
Based on the electromagnetic resonance characteristics of metamaterials, a polarization-independent radar cross section (RCS) metamaterial absorber is designed and fabricated.It is analyzed by the field distribution and inversion methods that the microwave absorption mechanism, The wave absorption method and the space wave method were used to test the wave absorption rate and the RCS characteristic.The theoretical analysis shows that under the action of the plane wave, the wave absorber provides electric resonance and magnetic resonance to a certain absorption frequency at different positions respectively, Different absorption wave frequencies, using different dielectric layers to provide the main energy loss, thus effectively weakening the electromagnetic coupling and ensuring strong absorption characteristics over a wide frequency band.Experimental results show that the wave absorption rate of the three-layer structure absorber reaches 90 The bandwidth of more than% is 4.25 times that of the single-layer structure, and the bandwidth of RCS reduced by more than 10 dB is 5.1%. The cell size is 0.17λ and the thickness is only 0.015λ. The low RCS characteristic of the absorber is also polarization independent, Wide angle of incidence characteristics, and by changing the sandwich structure absorber can work to achieve flexible bandwidth adjustment.