Design of Artificial Metal Rough Surfaces for Ultrawideband RCS Reduction Based on Approximate Ray Launching Geometrical Optics

This letter proposes an approximate ray launching geometrical optics (ARL-GO) method for designing the profiles of 1-D and 2-D artificial metal rough surfaces (AMRSs) to realize ultrawideband radar cross section (RCS) reduction. The method transforms AMRS's height and gradient into the electromagnetic wave's amplitude and phase, achieving fast calculation of AMRS's RCS. Combined with the constrained multiobjective particle swarm optimization (PSO) algorithm, the AMRSs can format good diffuse scattering of incoming plane waves. Under normal incidence, the final optimized polarization-insensitive 1-D and 2-D AMRSs can realize 20 dB RCS reduction at frequencies of above 7.6 GHz and 6.7 GHz, respectively, with no upper limit frequency. While the incident angle reaches 40°, the designed AMRSs can still achieve 20 dB RCS reduction above 10 GHz, achieving good stealth performance. The theoretical analysis, simulation, and experimental results are in good agreement.