Broadband, Polarization-Insensitive and Ultra-Thin Metasurface-Based Radar-Absorbing Structure for Radar Cross-Section Reduction of Planar/Conformal Hotspots

In this article, a broadband, polarization-independent and ultra-thin radar-absorbing structure (RAS) is proposed for the radar cross-section reduction (RCSR) of both planar and conformal scattering hotspots. The absorption characteristics and radar cross-section (RCS) performance of the novel metasurface-based RAS are analyzed in detail for both TE and TM polarization over a wide range of incident angles. The equivalent circuit model corresponding to the proposed unit cell is included as well. Further, the novel ultra-thin RAS (thickness of 0.043λ at the lowest operating frequency) was fabricated using a flexible substrate in both planar and conformal configurations, and the periodic pattern remained intact (without delamination) when applied over conformal geometries. The measurement results show that the percentage of power absorbed by the proposed structures (both planar and conformal) is greater than 80% in the frequency range of 8.2–12.2 GHz for both polarizations even at oblique angles of incidence. In addition, they provide more than 10 dB RCSR in comparison with their metallic counterparts of identical dimensions.