基于互导纳法设计了A夹层频率选择表面(FSS)罩壁结构并制作了平面试件和圆锥形雷达罩试件,验证了复合结构的一体化加工工艺。在微波暗室中对平板试件和FSS锥形罩进行了测试将部分测试结果与计算结果进行了比较。结果表明，A夹层加载的双层FSS带内传输损耗较小,具有一定的平顶特性,且带宽的入射角和极化稳定性较好。60°斜入射时,双层FSS的TE和TM极化的-3 dB带宽之差比相应单层FSS减小1.3 GHz;蜂窝夹芯层厚度较大时(1/4λ左右),A夹层两侧的单层FSS之间耦合较小,因而双层FSS的谐振频率与单层相同。曲面FSS雷达罩的传输特性与天线极化状态和测试方位均有关系,在主极化平面内与平面试件的结果一致,表明局部近场测试时曲率的影响较小,设计时可采取局部平面近似。

A-sandwich radome structure with Frequency Selective Surface (FSS) was designed based on a mutual admittance approach, and the experimental objects of planar and conical radome were manufactured, which verified the integral technique of composite structures.Tests on the planar sample and FSS conical radome were carried out in an anechoic chamber, and some of which were compared with computation results.The results show that the dual-layer FSS loaded by A-sandwich structure has a small loss of in-band transmission with flat-peak characteristics, and the incidence angle and polarization of the bandwidth show a good stability.At a large incidence angle of 60°, the difference of -3 dB bandwidth between TE and TM polarizations of a dual-layer FSS is 1.3 GHz less than that of sigle-layer FSS.When the thickness of honeycomb sandwich layer is large (about 1/4λ), the coupling between the two side FSS layers is little, so dual and single layer FSSs have the same resonant frequency.Furthermore, the transmission properties of the curved FSS radome are related to both antenna polarization and incident direction,and the experimental results of the radome in the main polarization plane are consistent with that of the planar objects.These results indicate that the influence of curvature is quite small in a test of local near-field, so the local planar approximation can be used in the design stage.