An Ultra-Wide Band Polarization-Independent Random Coding Metasurface for RCS Reduction

In this paper, a novel ultra-wide band (UWB) random 3-bit coding metasurface with polarization independence has been designed to realize radar cross-section (RCS) reduction. The proposed structure consists of polarization conversion metasurfaces (PCMs), which possess the capability of rotating linear polarization waves to their orthogonal ones in an UWB. The polarization-independent property can be attributed to the random rotation angle of each constituting unit. Due to the randomness of 3-bit coding and rotation angle of each element, the divergence of the reflected beam is greatly improved. In addition, the effect of RCS reduction with respect to the unit period length and the unit position are also discussed. Finally, a prototype is fabricated and measured to validate the simulation. The experimental results demonstrate that an ultra-wide band RCS reduction over 10 dB, ranging from 18.3–42.2 GHz, can be attained by the proposed coding metasurface and the maximum reduction is 28.7 dB.