Dual-broadband flexible metasurface based on the staggered triangular checkerboard layout for RCS reduction

A dual-band staggered triangular checkerboard metasurface (STCM) with flexibility is proposed for the radar cross section (RCS) reduction. The designed STCM can obtain greater than 10 dB dual-broadband RCS reduction at the two side bands and high efficiency of mirror reflection in the center band whether in planar or cylindrical conformal cases. Compared with a traditional square checkerboard metasurface (TSCM) of the same size, the simulation results indicate that the STCM in the planar case shows stronger vertical RCS reduction, with a maximum improvement of 11.85 dB. Especially, the proposed STCM covered on the cylinder with the radius (R) of 90 mm can achieve over 10 dB RCS reduction in 8.2-11.4 GHz and 15.2-19.1 GHz, and the corresponding relative bandwidth (RB) is 32.7 % and 22.7 %, which is superior to other research results. The scattering characteristics of the cylinder conformal case become better ith the increase of R under the case of a certain size of the STCM. Furthermore, RCS reduction exceeding 7 dB can be obtained in 11.2-13.1 GHz (RB = 15.6 %) and 15.7-19.1 GHz (RB = 19.5 %) when the STCM is applied on the saddle surface. A prototype is fabricated and measured. The experiment result shows the STCM can achieve more than 10 dB RCS reduction in 8.6-11.7 GHz (RB = 30.5 %) and 15.2-18.7 GHz (RB = 20.6 %) when wrapped around a cylinder with R = 90 mm, which almost coincides with numerical simulation. The proposed STCM shows promising application prospects in electromagnetic (EM) stealth, microwave communication and conformable stealth devices.