基于矩量法分析准光学波段的分形频率选择表面  

Design Methods of Fractal Frequency Selective Surface Based on Quasi-Optical Waveband

作　　者：王珊珊[1,2] 高劲松[1] 冯晓国[1] 梁凤超[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,北京100049

出　　处：《光学学报》2011年第4期199-203,共5页Acta Optica Sinica

基　　金：中国科学院国防创新基金(CXJJ-149)资助课题

摘　　要：在准光学系统中,频率选择表面(FSS)主要作为高效分离准光学高斯波束的无源滤波器运用于多频率信道。利用分形结构局部与整体的自相似性将分形理论应用于FSS领域,将分形结构作为FSS的周期单元使单屏FSS具有多频谐振的特性,从而实现简易、多频无源带通滤波器件的设计。以常见的十字单元为例,经过递归产生二阶十字分形单元,结合Floquet周期理论和边界条件应用矩量法对分形FSS的传输特性进行理论分析与设计,获得在准光学波段58GHz和145GHz处谐振的单屏FSS,谐振频率的透射率均大于95%。通过分析改变分形FSS的结构参数对其传输特性的影响,得出二阶十字FSS的第一谐振频率f1主要由原始单元臂长L1决定而第二谐振频率f2对迭代单元臂长L2较敏感,f1的传输特性较稳定的设计规律。考察了电磁波入射角度与极化方式变化时十字分形FSS频率响应的稳定性。Frequency selective surface（FSS） is mainly used as passive filters to separate optical Gaussian beam in quasi-optical system.The multiband FSS on single screen can be designed using self-similar fractal elements as periodic cells.Take cross element for example we can obtain second-order cross fractal element by recursive algorithm.The method of moments is employed to characterize the transmission properties of fractal band-pass FSS combining with Floquet＇s periodic theory and boundary conditions.The transmissivity of multiband FSS with resonant frequencies of 58 GHz and 145 GHz are all above 95%.After analyzing the influence of changing the structural parameters of fractal FSS on its transmission characteristic,it is known that the first resonant frequency f1 is decided by the arm length L1 of the original element and the second resonant frequency f2 is sensitive to the arm length L2 of the iterative element,the stability of the transmission characteristics of f1 is better than f2.We examine the stability of the fractal FSS frequency response when changing the incident angle and polarization of the electromagnetic wave.

关 键 词：表面光学 频率选择表面 分形单元 多频谐振 矩量法 

分 类 号：TN975[电子电信—信号与信息处理]