Dual-Mechanism Absorptive Metasurface with Wideband 20 dB RCS Reduction

This paper presents a dual-mechanism method to design a single-layer absorptive metasurface with wideband 20 dB RCS reduction by simultaneously combining the absorption and phase cancellation mechanisms. The metasurface comprises two kinds of absorbing unit cells with 10 dB absorption performance but different reflection phases. The impedance condition for 20 dB RCS reduction is theoretically analyzed considering both the absorption and the phase cancellation based on the two unit cells, and the relationship between the surface impedance and the reflection phase/amplitude is revealed. According to these analyses, two unit cells with absorption performance and different reflection phases are designed and utilized to realize the absorptive metasurface. Numerical and experimental results show that the single-layer absorptive metasurface features wideband 20 dB RCS within 11.5–16 GHz with a thickness of only 3 mm.