基于双层介质AMC的宽带隐身超表面

A Stealth Metasurface with Wide Band Based on Double Layer Dielectric AMC

针对目前由人工磁导体(AMC)构成不同结构的隐身超表面带宽较窄和雷达散射截面(RCS)减缩量较小的问题,设计了一种基于双层介质AMC单元的棋盘结构宽频带隐身超表面。通过将AMC单元的介质设置为具有不同介电常数的双层介质,使两个单元的反射相位突变点和反射相位零点的频率值重合,进一步拓宽了满足理想相位差的频率范围,从而拓展了RCS减缩带宽,并且将单元厚度减小到3 mm。仿真结果表明:该隐身超表面在4.8 GHz~13.5 GHz的频带范围内具有RCS减缩效果,相对带宽为95.1%;在5.6 GHz~13.2 GHz的频带内减缩效果最好,减缩量达到了10 dB以上,相对带宽为80.9%。该结论验证了基于双层介质基板的AMC单元进行厚度更薄的隐身超表面设计的可行性,为进一步提高超表面的RCS减缩带宽提供了新思路。

In order to solve the problem that the bandwidth of stealth metasurface with different artificial magnetic conductors(AMC)is narrow and reduction of radar cross section(RCS)is small at present,a wide band stealth metasurface with chess board structure is designed based on double layer dielectric artificial magnetic conductor unit.By setting the medium of AMC unit as a double layer medium with different dielectric constants,the frequency of the reflection phase mutation point and the reflection phase zero of the two units are coincident,which further widens the frequency range satisfying the ideal phase difference and thus expands the reduction bandwidth of RCS,and the unit thickness is reduced to 3 mm.The simulation results show that the stealth metasurface has the reduction of RCS in the frequency band from 4.8 GHz to 13.5 GHz,and the relative bandwidth is 95.1%.The best reduction effect appears in the range of 5.6 GHz~13.2 GHz,where the reduction amount of RCS reaches more than 10 dB and the relative bandwidth is 80.9%.This conclusion verifies the feasibility of designing thinner thickness of the stealth metasurface based on AMC unit with double layer dielectric substrate,and a new idea is provided by results for designing more effective metasurface.