为了实现8～14μm波段低反射率涂层与超材料吸波体的兼容隐身,探究了影响低发射率涂层与超材料兼容性能的关键因素.采用IR-2型发射率测试仪测定涂层在8～14μm波段的发射率,用弓形法测量了超材料涂覆涂层前后的反射损耗曲线,并采用矢量网络分析仪测试了涂层电磁参数.结果表明,涂覆低发射率涂层后,可将超材料吸波体的红外发射率降至0.126,但是其对超材料吸波体原有吸波特性影响较大,平均反射损耗以及吸收带宽都有所减小.在涂层4个电磁参数中,介电常数实部为影响低发射率涂层与超材料兼容的关键因素,低发射率涂层的介电常数实部较高,导致本征阻抗较小,与自由空间的阻抗不匹配,对雷达波的反射较多,涂覆后对超材料吸波体原有反射损耗特性影响大.%To realize the compatible stealth of low-emissivity coatings in the 8-4μm wave band with the metamaterial microwave absorbers, the key factor influencing the compatible property of the low-emissivity coatings was investigated. The coating emissivity in the 8-14μm band was measured by IR-2 and the reflection loss curve of metamaterial absorbers(before and after being coated) was tested by the NRL-arc method. In addition, the electromagnetic parameters of coatings were measured by using the vector network analyzer. The results of experimental investigation indicated that after being coated by the low-emissivity coatings, the emissivity of the metamaterial is reduced to 0.126, and the coating restricts the original wave-absorbing property(the average reflection loss and absorption bandwidth are both decreased). Among four electromagnetic parameters, the real part of the permittivity is the most critical factor constraining the compatible stealth property of low-emissivity coating with metamaterials. The real part of the permittivity of low-infrared-emissivity coatings is so high that it results in allow impedance of the coatings, which leads to under matching impedance with the free space. As a result, the low-infrared-emissivity coatings reflect more radar waves and exercise a great influence on the original reflection loss property of the metamaterials microwave absorbers.
展开▼
