Y孔分形频率选择表面的设计  

Design methods of Y aperture fractal FSS

作　　者：王珊珊[1,2] 高劲松[1] 冯晓国[1] 赵晶丽[1] 

机构地区：[1]中国科学院长春光学精密机械与物理研究所,中国科学院光学系统先进制造技术重点实验室,吉林长春130033 [2]中国科学院研究生院,北京100039

出　　处：《光学精密工程》2011年第5期959-966,共8页Optics and Precision Engineering

基　　金：中国科学院国防创新基金资助项目(No.CXJJ-149);中国科学院优秀博士论文、院长奖获得者科研启动专项基金资助项目(No.076231J070)

摘　　要：提出了将分形理论应用于频率选择表面(FSS)设计,使单屏FSS具有多频谐振特性,以进一步满足现代通信设备对多频带及集成化的要求。首先,以结构对称、抗交叉极化特性好的Y孔单元为例,经过递归、迭代产生二阶Y孔分形单元,给出计算单元几何分布的公式。然后,结合Floquet周期条件,应用全波周期矩量法得到描述FSS表面电流分布的电场积分方程,定量分析了入射电磁波在不同极化方式下Y孔分形FSS单元的极子长度、孔径宽度等结构参数及排布方式对其频率响应特性的影响。最后,采用成熟的镀膜、光刻工艺制备Y环分形FSS样件并在半电波暗室进行FSS传输特性测试。结果表明,第一谐振波长的经验估算值约为0.79×(4倍极子长度),孔径宽度W由1mm增至1.5mm时,带宽展宽了650MHz,角度稳定性对单元排布方式较敏感。得到的测试结果与数值结果一致,表明单屏分形FSS具有多频谐振的特性,其透过率及-3dB带宽均可通过参数优化满足工程应用基本要求。The fractal elements were exploited to design single layer Frequency Selective Surfaces（FSSs） as multi-band pass filters to meet the multi-band and integration requirements of the communication apparatus.Firstly,the geometry expression of a Y aperture fractal FSS with a symmetry structure and anti-cross polarization was proposed by recursion and iterative operations.Then,combined with Floquet theory and the full-wave periodic moment method,an electric field integral equation to describe the current distribution of the FSS surface was obtained to quantitatively analyze the frequency response of the lattice and the structural parameters of Y aperture fractal FSS,such as pole length,aperture width,and the different polarizations of incident electromagnetic wave.Finally,a FSS sample was achieved by the photolithography and experiments in the anechoic chamber.Experimental results show that the estimation empirical constant κ is 0.79 for designing the resonant frequencies of FSS and the bandwidth expands to 650 MHz when the width of aperture varies from 1.0 mm to 1.5 mm.Moreover,the effects of incident angle is highly sensitive to the lattice of the periodic unit cell.Obtained results are well coincident with that of theoretical calculation,which means the single-layer fractal FSS with multiband characteristics can satisfy the engineering requirements after parameter optimization.

关 键 词：频率选择表面(FSS) 分形单元 周期矩量法 多频带 

分 类 号：TN957[电子电信—信号与信息处理] TN713[电子电信—信息与通信工程]