Vehicle metastructure skin designed by overall-parameter evolutionary optimization for broadband microwave absorption

Metastructure fabricated by electromagnetic lossy materials has been proved to be an effective approach to achieve broadband microwave absorption in civil and military usage. However, complicated structure surface of metastructure hinders further applications for deployment on vehicles and aircraft as aerodynamic properties are poor and turbulence will be generated. Herein, a vehicle metastructure skin (VMS) is proposed to maintain even surface of metastructure for better aerodynamics without sacrificing broadband absorption performance. An overall-parameter evolutionary optimization scheme is proposed to solve severe impedance mismatch between metastructure and air with quartz fiber reinforced composite (QFRC) as aerodynamic skin. The fabricated VMS achieved −10 dB absorption performance in 1.26–25.8 GHz. Under sudden fluctuation of surface impedance, extensional absorption in low frequency range below 2 GHz is realized. Wide-angle oblique broadband absorption is also achieved in TE and TM polarization. With the proposed optimization strategy, the aerodynamic problems brought by surface turbulence in secondary structure of metastructure are solved.