Simultaneous reduction of microwave reflection and infrared emission enabled by a phase gradient metasurface

Metasurfaces have shown promising applications in radar-infrared compatible stealth because of its superior electromagnetic wave control capabilities, but, to date, the majority of designs still suffer from the defects of large thickness, limited working bandwidth, relatively high infrared emissivity and so on. Here, an exotic phase gradient metasurface (PGM) is proposed to achieve low microwave reflection and low infrared emission concurrently, which has a small thickness of about 0.10λ₀. The microwave reflection reduction larger than 10 dB in 14-20 GHz is attributed to the anomalous reflection for arbitrary LP incident waves, and the infrared emissivity less than 0.28 from 3 to 14 µm is due to the indium-tin-oxide (ITO) with low infrared emissivity and high filling ratio. Also, the designed PGM can also realize beam deflection for orthogonal CP waves because of the meta-atoms' isotropic characteristics. Our methodology is fully verified by numerous simulations and experiments and may open a new avenue for radar-infrared compatible stealth research.