Ku/Ka波段双通带频率选择表面雷达罩设计研究

为了满足现代通信设备多频带及集成化要求，基于耦合机理和谐振机理，在实心半波壁雷达罩和A 夹层雷达罩等效平板基底上设计了一种由容性表面（内嵌谐振单元）-感性表面-容性表面（内嵌谐振单元）-等效基底级联而成的Ku/Ka波段双通带频率选择表面结构. 根据FSS的物理结构建立了等效电路模型，分析了滤波机理，利用全波分析软件计算了两种FSS雷达罩的传输特性. 该结构基于容性表面与感性表面的耦合作用在Ku波段形成具有微型化特性的第一通带，基于两个容性表面内嵌的方环单元谐振在Ka波段形成第二通带，两通带透过率分别为89%，94.7%（实心半波壁FSS雷达罩）、88.2%/93.7%（A夹层FSS雷达罩），在0°–45°扫描范围内，两通带传输特性稳定. 在半波壁雷达罩的等效平板上制作了Ku/Ka双通带实验样件，利用自由空间法测试其传输特性，在制作误差允许的范围内，测试结果与仿真结果基本一致. 为研究通带间隔较宽的多频FSS 提供了理论和实验依据. 关键词： 雷达罩 频率选择表面(FSS) 双通带

Design and study on the dual-band radome with FSS operation at Ku-/Ka-band

In order to meet the multi-band and integration requirements of the communication apparatus, the coupling and resonance mechanism can be exploited to design a frequency selective surface (FSS), with two pass-bands at Ku-band and Ka-band, which is composed of three metallic layers and fabricated on a flat substrate equivalent to a solid wall radome or an A-sandwiched radome. According to the physical structure of the FSS, an equivalent circuit model is established to analyze the filtering mechanism, and the transmission characteristics of the radomes with FSS are obtained by using a full-wave analysis software. The first pass-band at Ku-band with miniaturization property can be achieved by coupling the electric and magnetic field of the three surfaces, while the second pass-band at Ka-band can be achieved by the resonance of the square loop slots embedded in the capacitive surfaces. The transmissions of the solid wall radome and A-sandwiched radome with FSS are 89% and 94.7% at Ku-band, and 88.2% and 93.7% at Ka-band, respectively. When the incident angle is varied from normal to 60°, the frequency response characteristics of the two pass-bands are stable. Finally, the experimental results of the prototype with a solid substrate measured in free-space environment are in good agreement with the simulated values. The proposed radome structure with FSS, which is based on the coupling and resonance mechanism, can achieve two stable pass-bands at Ku-/Ka-band. This may provide some theoretical and experimental assistance for the study of the multi-band and wide band spacing FSS.
Keywords： radome frequency selective surfaces (FSS) dual-band