Ultra-wideband radar cross-section reduction achieved by means of diffusion and absorption

In this work, an ultra-wideband absorptive coding metasurface (ACM) is proposed for radar cross-section (RCS) reduction. The ACM is composed of two types of lossy coding elements arranged in an appropriate manner, the two types of lossy coding elements both have a certain wave-absorbing performance due to ohmic loss, and the main reflection phases will differ by almost 180^° under same incidence in an ultra-wide frequency arrange. Therefore, the ACM can achieve ultra-wideband RCS reduction by means of diffusion and absorption. The simulation results demonstrate that the RCS of the ACM under normal incidence with arbitrary polarization can be effectively reduced in the ultra-wide frequency band of 7.5–43.0 GHz with a relative bandwidth of 140.6%; moreover, when the incident angle is increased to 45^°, an ultra-wideband RCS reduction can still be achieved. Finally, an experimental prototype is fabricated and measured, and the performance of the ACM is experimentally validated.