Liu Chuangji, Xu Yingjie, Huang Beiqing, Zhang Wan, Wang Yuxin
College of Printing and Packaging Engineering, Beijing Institute of Graphic Communication, No. 1 (Band-2) Xinghua Street, Beijing 102600, China.
Polymers (Basel). 2024 Sep 23;16(18):2677. doi: 10.3390/polym16182677.
K-band radar waves have high penetration and low attenuation coefficients. However, the wavelength of this radar wave is relatively short; thus, designing and preparing both broadband and wide-angle radar wave absorbers in this band presents considerable challenges. In this study, a resin-based K-band radar wave absorber with a biomimetic lotus leaf structure was designed and formed by UV curing. Here, microscale lotus leaf papillae and antireflection structures were prepared using a DLP 3D printer, and the contact angle between the material and water droplets was increased from 56° to 130°. In addition, the influence of the geometric parameters of the lotus leaf antireflection structure on the electromagnetic absorption performance and mechanical strength was investigated. After simulation optimization, the maximum electromagnetic loss of the lotus leaf structure 3D-printed sample was -32.3 dB, and the electromagnetic loss was below -10 dB in the 20.8-26.5 GHz frequency range. When the radar incidence angle was 60°, the maximum electromagnetic loss was still less than -10 dB. The designed lotus leaf structure has a higher mechanical energy absorption per unit volume (337.22 KJ/m) and per unit mass (0.55 KJ/Kg) than commonly used honeycomb lightweight structures during the elastic deformation stage, and we expect that the designed structure can be used as an effective lightweight material for K-band radar stealth.
K波段雷达波具有高穿透性和低衰减系数。然而，这种雷达波的波长相对较短；因此，在该波段设计和制备宽带和广角雷达波吸收体面临着相当大的挑战。在本研究中，设计了一种具有仿生荷叶结构的树脂基K波段雷达波吸收体，并通过紫外光固化成型。在此，使用DLP 3D打印机制备了微米级的荷叶乳头和减反射结构，材料与水滴之间的接触角从56°增加到了130°。此外，还研究了荷叶减反射结构的几何参数对电磁吸收性能和机械强度的影响。经过模拟优化，3D打印的荷叶结构样品的最大电磁损耗为-32.3 dB，在20.8-26.5 GHz频率范围内电磁损耗低于-10 dB。当雷达入射角为60°时，最大电磁损耗仍小于-10 dB。在弹性变形阶段，所设计的荷叶结构每单位体积（337.22 KJ/m）和每单位质量（0.55 KJ/Kg）的机械能吸收比常用的蜂窝轻质结构更高，并且我们期望所设计的结构能够用作K波段雷达隐身的有效轻质材料。
