Recent advances in material science and electronics led to the rapid development of communication devices and radar detection techniques resulting in an ever-increasing demand for improved stealth performance of air vehicles during scouts. Absorber design employing metastructure concept has recently become a popular approach to improving radar stealth performance. Metastructure permits the realization of desired absorption characteristics by careful design of geometrical structures and material compositions. In this study, a metastructure designed based on graphite SLS composite for radar absorption has been demonstrated. The unit cell of the proposed structure is simulated by COMSOL Multiphysics to determine the frequency-dependent absorption characteristic of the structure. It is fabricated by using a low-cost selective laser sintering technique of additive manufacturing technology. The prototype, while measured, shows effective absorption bandwidth of 1.04 GHz that is in reasonable agreement with the simulated response of 2.08 GHz. The optimized structure exhibits ≤ − 10 dB reflectivity within a broad frequency range extending from 7.60 GHz to 18.00 GHz under normal incidence in both TE and TM polarizations. Furthermore, the absorption performance under different polarizations and incident angles has been investigated. Results indicate that the absorber displays polarization indifference and exhibits a wide-angle of incidence tolerance of up to 45° in TE polarization and 30° in TM polarizations. In this paper, the feasibility of using graphite SLS material to design and 3D print a metastructure design for radar absorbing has been established as confirmed by the simulation and the measurement results. The advantages of low cost, ultra-broad operating band, wide-angle of incidence feature, and polarization insensitivity qualifies the proposed absorber for stealth and electromagnetic shielding applications.

中文翻译：

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宽带雷达吸收的增材制造的元结构设计

材料科学和电子学的最新进展导致通信设备和雷达检测技术的飞速发展，导致对侦察期间提高飞行器隐身性能的需求不断增长。采用元结构概念的吸收器设计最近已成为提高雷达隐身性能的一种流行方法。通过精心设计几何结构和材料成分，元结构可以实现所需的吸收特性。在这项研究中，已经证明了基于石墨SLS复合材料设计的用于雷达吸收的元结构。通过COMSOL Multiphysics对拟议结构的晶胞进行仿真，以确定该结构随频率变化的吸收特性。它是通过使用增材制造技术的低成本选择性激光烧结技术制造的。原型在测量时显示出1.04 GHz的有效吸收带宽，与2.08 GHz的模拟响应合理地吻合。经过优化的结构在TE和TM偏振的法线入射下，在从7.60 GHz扩展到18.00 GHz的宽频率范围内，具有≤− 10 dB的反射率。此外，已经研究了在不同偏振和入射角下的吸收性能。结果表明，该吸收剂表现出偏振无关性，并且在TE偏振和TM偏振方面表现出高达45°的入射耐受广角。在本文中，仿真和测量结果证实了使用石墨SLS材料进行3D打印和雷达吸收的元结构设计的可行性。低成本，超宽工作频带，入射角广的特性以及极化不敏感的优点使所提出的吸收器具有隐身和电磁屏蔽应用的资格。