为满足红外和雷达复合制导飞行器带外隐身的要求，设计了一种ZnS基底上的红外高通雷达带通的频率选择表面( FSS)组合膜。设计并分析了作为初始结构的电感性网栅薄膜，运用含阻抗边界条件的谱域Galerkin法分析了网栅膜基底上的开孔十字FSS结构，该结构谐振频点为31.75 GHz，透射率为-0.38 dB，其对应的理想导体(PEC)表面FSS的谐振频点为33 GHz；为提高此组合结构的红外透射率，运用薄膜光学理论设计了由YbF3与ZnSe两种膜料组成的红外增透膜，膜层厚度为1.085 μm。结合光刻与镀膜工艺制作了实验件，测试表明，该组合薄膜在测试雷达频段平均传输系数小于-7.51 dB（谐振频点外），在谐振频点31.5 GHz的透射率达到了-0.63 dB；在长波红外平均透射率达到了87.95%。

To shield the detection radar wave for radar/infrared combined guidance weapons, an idea of designing a kind of combining frequency selective surface (FSS) coatings is proposed on ZnS substrate. The coatings are not only infrared transparent, but also have bandpass properties in radar wave band. An inductive mesh which is treated as the initial structure is designed and analyzed. An FSS structure with aperture element of cross shape is designed and analyzed by a socalled Galerkin′s method in the spectral domain. The resonance frequency of this FSS structure is 31.75 GHz, whose transmittance is about -0.38 dB. The resonance frequency of FSS on perfect conductor (PEC) surface which has the same parameters is 33 GHz. Antireflection coatings are designed by optical coatings theory with two coating materials to improve the infrared transmittance of this combination structure. The total layers′ thickness is 1.085 μm. The sample is fabricated by depositing coatings and lithography. The test results indicate that the transmittance at radar central resonant frequency of 31.5 GHz is about -0.63 dB, and the average transmittance (out of central frequency) is lower than -7.51 dB . The average transmittance is 87.95% in longwave infrared region.