【作者】 王秀芝；

【导师】 高劲松；

【作者基本信息】 中国科学院研究生院(长春光学精密机械与物理研究所) ， 光学， 2014， 博士

【摘要】 频率选择表面(Frequency Selective Surface，FSS)是一种一维或二维周期结构，具有带通或带阻空间滤波特性，被广泛应用于雷达罩隐身中。小型化频率选择表面(MEFSS)是周期单元尺寸远小于工作波长的FSS的统称，是FSS发展的一个新方向。与传统的FSS相比，MEFSS具有更小的单元尺寸和更高的角度稳定性，在有限空间、局部小区域、非平面波照射等特殊环境下均能获得理想的滤波特性，在多频、宽频、可调谐FSS设计上具有很大的发展潜力。论文以MEFSS在末制导雷达罩上的应用为需求背景，围绕MEFSS的物理机制、设计原理和方法等关键问题进行了深入的理论研究、计算仿真和实验验证，拓展了MEFSS在宽通带和双通带设计中的应用。论文主要研究工作如下：1.首先采用电子运动理论从微观上研究了FSS的工作机制，其次采用“场”的观点和“路”的观点从宏观上研究了FSS的滤波机理。从“场”的观点出发，基于Floquet定律研究了FSS的传播波、凋落波和栅瓣的传播规律；利用FSS栅瓣图，推导了FSS具有稳定滤波特性的条件；基于周期单元谐振模式相关理论研究了周期单元上电场和电流的分布特征，为FSS单元图形设计提供理论依据。从“路”的观点出发，重点研究了FSS等效电路模型的建立与分析，采用对全波仿真曲线拟合的方法获取了复杂FSS结构的LC参数，并验证了参数的有效性和方法的可行性，为设计和优化阶段FSS传输特性的快速计算提供参考。2.研究了基于容性表面与感性表面耦合机制的MEFSS。选取三种典型MEFSS结构，开展了Ku波段带通MEFSS仿真设计研究，总结了耦合型MEFSS的设计规律和滤波特性。以半波壁和A夹层雷达罩结构作为应用平台，研究了MEFSS在隐身雷达罩上的应用。3.将耦合型互补双屏结构与Butterworth型对称双屏结构相结合，设计出具有宽通带特性的MEFSS。该结构由容性表面-感性表面-容性表面的三屏级联而成，采用Y形修正单元和正三角形(60°)布阵方式，具有小型化、宽通带和最平坦(Butterworth)响应滤波特性。论文设计了工作带宽涵盖整个X波段或Ku波段的MEFSS，分析了参数对滤波特性的影响，最后进行了实验验证，拓展了MEFSS在宽通带FSS设计中的应用。4.将耦合机制与谐振机制相结合，利用容性表面(内嵌谐振单元)-感性表面-容性表面(内嵌谐振单元)三屏级联结构设计了Ku/毫米波波段双通带MEFSS。以半波壁和A夹层结构雷达罩为背景，将该设计成功应用到Ku/Ka双波段MEFSS雷达罩中。这种MEFSS具有通带间隔较宽、相互独立的特点，拓展了MEFSS在多频FSS设计中的应用。5.为了进一步缩减FSS单元尺寸，论文研究了基于集总元件加载的MEFSS。集总元件包括无源器件和有源器件两大类。基于无源器件中的集总电容和集总电感加载设计了MEFSS，单元尺寸缩减至中心波长的1/28以下，具有优越的小型化特性，同时，通过优化还获得了极化分离特性。基于有源器件中的PIN二极管加载设计了可调谐MEFSS。该MEFSS在二极管工作频率允许的情况下，可以在保持Ku波段带通特性不变的同时，实现S波段通带开关功能。最后设计制备了在S波段具有通带开关特性的MEFSS结构。这种可调谐MEFSS在雷达罩带内隐身中具有广阔的发展前景。论文针对末制导雷达罩隐身的诸多需求(如多频、宽波段、可调谐等)，开展MEFSS研究。不仅完善了MEFSS设计理论，还拓展了MEFSS实现途径和应用领域，为MEFSS隐身雷达罩的工程应用提供了理论和实验参考。更多还原

【Abstract】 Frequency Selective Surface, which has been widely used in stealth radome, is aone-dimensional or two-dimensional periodic structure with band-pass or band-stopproperties. Miniaturized frequency selective surface (MEFSS) whose unit cell size ismuch smaller than its working wavelength is a new direction for FSS development.Compared with traditional FSS, MEFSS has miniaturized elements and stableresonance properties. It can be applied under special circumstances, such as in thelimited space, at a small local area, or non-plane wave illumination. MEFSS is ofgreat potential to design a structure with multiband, wideband and tunable properties,etc.On the back ground of the impending requirement of terminal guidance radome,this dissertation has discussed the physical mechanism, design principles andmethods of MEFSS based on in-depth theoretical analysis, numerical simulationsand practical experiments. And the main contents are as follows:1. According to the theory of electron movement, the operation mechanism ofthe FSS is analyzed on the view of microcosm. And from a macroscopic perspective,the filter mechanism of the FSS is studied based on the theory of field and circuit,respectively. Based on theory of field, the transmission properties of FSS, mainlyabout propagating wave, evanescent wave and grating lobes, are studied by using theFloquet modes. The necessary condition of getting stable filtering characteristics has been deduced from FSS’s grating lobe graph. And the influences of the mode on thetransmission properties of FSS are analyzed. Based on the theory of circuitry, it isstudied about how to establish equivalent circuit model of FSS and analyze thefiltering mechanism. This part unveils that it is feasible to analyze the complex FSSstructure by the equivalent circuit model based on curve-fitting process. It will givesome references for the quick calculation of FSS transmission characteristics duringdesign and optimization stages.2. The MEFSS which is based on the mechanism of coupling the capacitivesurface and the inductive surface is studied. Moreover, three typical MEFSSstructures are used to design Ku-band MEFSS. From that, the design principles andideas of MEFSS that work at Ku-band are obtained. Then MEFSSs with a pass-bandat Ku-band, which are applied to a solid wall radome and A-sandwiched radome, aredesigned and analyzed.3. Based on the studies of the complementary and symmetric structures, awideband MEFSS is presented. It is composed of three metallic layers with skewedarrays (60°) of modified tripoles. This MEFSS has the properties of miniaturizedelements, wider bandwidth and maximally flat (Butterworth) response. The MEFSSswith a desired wide pass-band at least at X or Ku-band are designed, and theprinciples of operation, the influences of the parameters, the experimental values ofthe fabricated prototype are presented and discussed. It is useful for designingwideband FSSs with flat top and sharp cut-off.4. The coupling and resonance mechanism are exploited to design MEFSS. Thedesigned structure is composed of three metallic layers, and can obtain twopass-bands at Ku-band and millimeter-wave region. Using it to design stealthradome, a MEFSS on the solid wall radome or A-sandwich radome substrate isdesigned and fabricated. The proposed radome structure with FSS can achieve twostable pass-bands at Ku-/Ka-band. It is useful for designing multi-band and wideband spacing FSS.5. In order to further reduce the unit size of the FSS that especially worked at low frequency, the MEFSS loading lumped components are studied. Using thepassive lumped components—capacitances and inductances, the unit size of thedesigned MEFSS can reduce to λ0/28, and by optimization, this structure has aproperty of polarization separation at the same time. Using the active lumpedcomponents—PIN diodes, as long as the diode working frequency allows, thedesigned MEFSS is electronically switchable between reflective and transparentstates at S-band by switching PIN diodes to ON and OFF state, and always has apass-band at Ku-band. It is useful for designing electronically switchable stealthradome.In this dissertation, the study of MEFSS is mainly prepared for the special needsof stealth radome, such as wideband, dual-band with wide band spacing,electronically switchable at crucial frenquency, etc. It not only improves the designtheory of MEFSS, but also expands the approaches and applications of MEFSStechnology. And it provides some theoretical and experimental references for theapplication of MEFSS in stealth radomes.更多还原