Absorption and cancellation radar cross-section reduction metasurface design based on phase- and amplitude-control

Wider band and deeper radar cross section (RCS) reduction by lower profile is always a very noticeablesubject in stealth material researches. Most of researchers have designed and measured the RCS reductionbandwidth with 10 dB standard, that is, the return energy is reduced by 90%. In this paper we present a dual-mechanism method to design a single-layer absorptive metasurface with wideband 20-dB RCS reduction bysimultaneously combining the absorption mechanism and the phase cancellation mechanism. Firstly, theimpedance condition for 20-dB RCS reduction is theoretically analyzed considering both the absorption and thephase cancellation based on the two unit cells, and the relationship between the surface impedance and thereflection phase/amplitude is revealed. According to these analyses, two unit cells with absorption performanceand different reflection phases are designed and utilized to realize the absorptive metasurface. Then, wesimulate the plane case and the cylinder case with the designed flexible metasurface and compare them with thecounterparts with equal-sized metal. Finally, the sample is fabricated and characterized experimentally to verifythe simulated results. Both numerical and experimental results show that the 7-mm-thick single-layerabsorptive metasurface features a wideband 20-dB RCS within 6.10-12.15 GHz (66%). Our designed metasurfacefeatures wideband, 20-dB reduction, polarization insensitivity, light weight and flexible, promising greatpotential in real-world low-scattering stealth applications