A Hybrid Mechanism Metasurface Based on Absorption and Phase Cancellation for Ultra-Wideband RCS Reduction

This paper proposes a hybrid mechanism based on phase cancellation and absorption to design a metasurface with ultra-wideband 10 dB radar cross-section (RCS) reduction from 6 to 64.7 GHz (171%). At high frequencies of 15–64.7 GHz, 10 dB RCS reduction is achieved by a phase cancellation mechanism, which is realized by arranging a perfect electric conductor (PEC) to form an arrayed structure with varying heights. At low frequencies of 6–15 GHz, 10 dB RCS reduction is achieved by the absorption mechanism, which is realized by designing a rotationally symmetric dual-pattern absorber. The coupled mode theory (CMT) is used to explain the absorption mechanism. Additionally, it is found that a 180° phase difference is obtained by two different patterns to enhance RCS reduction in the high-frequency band of 28–35 GHz. Finally, the phase cancellation and absorption mechanisms are combined to achieve an ultra-wideband 10 dB RCS reduction from 6 to 64.7 GHz, which is realized by integrating the absorber into the arrayed structure to form the ultra-wideband RCS reduction metasurface. The designed metasurface has a compact size (subwavelength), and a thin profile with 0.105λ_L.