An optical-transparent metamaterial for high-efficiency microwave absorption and low infrared emission

An optically transparent metamaterial structure with simultaneously broadband microwave absorptivity and low infrared (IR) emissivity is proposed. Two specifically designed optically transparent metasurfaces were combined to realize radar and IR bi-stealth. One was designed to control the microwave absorption though properly modifying the impedance and resonance peaks of the meta-atom. The other was designed to control the IR radiation. Within a wide incident angle of +/- 60 degrees, the proposed structure displays high absorptivity greater than 90% in the region of 6.28-12.29 GHz for TE polarization. For TM polarization, the absorptivity in the region of 7.19-15.26 GHz is greater than 90%. The IR emissivity of the metamaterial structure is about 0.30 in the IR region from 3 mu m to 14 mu m. The perfect consistency between experimental results and simulation results demonstrates that the proposal has practical application of multispectral stealth technology.