A transparent and flexible metasurface with both low infrared emission and broadband microwave absorption

Researches on radar and infrared stealth compatibility have drawn much attention in recent years. In this work, a flexible metasurface with low infrared emission, broadband microwave absorption as well as high optical transmission is simultaneously achieved. The whole structure is composed of an infrared shielding layer (IRSL), a radar absorption layer (RAL), a substrate and a backplane, and the total thickness is only 3.5 mm. Based on the impedance matching theory, the microwave absorption higher than 90% can be achieved in the radar waveband ranging from 7.3 to 18.8 GHz, corresponding to a relative bandwidth of 88.1%. By using a conductive patch array as the IRSL, a low infrared emissivity of 0.49 can be realized in the infrared region from 8 to 14 μm. Moreover, by rational designing both the structures and materials, the metasurface in this work cannot only achieve bi-stealth functions with low infrared emission and broad microwave absorption, but also shows optically transparent and flexible properties, thus quite suitable for practical applications. Both the simulated and experimental results suggest that the proposed metasurface is promising in the multispectral stealth fields.