Ultra-thin and high temperature NiCrAlY alloy metamaterial enhanced radar absorbing coating

In this article, we present an enhanced metamaterial radar absorbing coating (MRAC) which possesses good electromagnetic absorption performance and ultra-thin thickness at high temperatures. The absorber is composed of radar EM absorbing coating and a layer of metamaterial. The metamaterial layer on the coating can enhance the absorption in two aspects. First, due to the coupling between the high permittivity coating and metamaterial layer, the impedance can match a smaller thickness better than a coating alone. Meanwhile, intense EM fields appear the surface of metamaterial pattern, which can also promote the absorption. The periodic pattern is made of special alloy which provides high temperature resistance quality. It is worth noting that the processing merely requires traditional plasma spraying, which ensures the practicability and feasibility. A 0.96 mm thick sample can achieve EM reflection loss below -5 dB at 800 °C over the whole X band. The experimental results are also consistent with the simulation, which successfully verifies the feasibility and proposes a competitive design for radar absorbing coatings (RAC).