Ultra-low radar cross-section realized by metasurface with nonuniform elements

AbstractA novel checkerboard metasurface is proposed to realize broadband ultra-low radar cross-section reduction (RCSR). The metasurface element is a non-uniform array which contains two uniform subarrays composed of 3 × 6 metallic patches. The reflection phases of the two subarrays can be compensated each other. Based on this characteristic, the non-uniform element reflects two orthogonally polarized waves with a phase difference shrinking to 180 ± 20° in a wideband from 11.2 to 23.0 GHz. When the non-uniform elements are arranged into a checkerboard structure, two co-polarized reflective waves with phase difference of 180 ± 20° are then generated for arbitrary polarized incident waves, resulting in an ultra-low RCS reduction. Simulation results show that the proposed checkerboard metasurface achieves at least 15 dB RCS reduction from 11.2 to 23 GHz (69%) for normal incident waves. The experimental results are good agreement with the simulations.KEYWORDS: Metasurfaceultra-low RCSnonuniform elements Disclosure statementNo potential conflict of interest was reported by the author(s).Data availabilityDate underlying the results presented in this paper are not publicly available at this time but may be obtained from the authors upon reasonable request.Statement of noveltyThe metasurfaces have shown great application prospects in radar cross-section reduction (RCSR). Many metasurfaces have been successfully designed to obtain 10 dB RCSR. With the development of various radar technologies, however, the 10 dB RCSR can no longer meet the stealth requirements. Therefore, deeper and wider radar cross-section (RCS) reduction are always the main concerns of stealth technology. Based on this consideration, we present a checkerboard metasurface that can realize broadband 15 dB RCSR. The metasurface element is a non-uniform patches array, which is composed of two uniform subarrays of 3 × 6 metallic patches. The reflection phases of the two subarrays can be compensated each other, which makes the non-uniform element reflect two orthogonally polarized waves with a phase difference a lot closer to 180o (180 ± 20o) in a wideband. Then the phase cancelation mechanism is generated by orthogonally arranging the non-uniform element into a checkerboard structure, resulting in ultra-low RCS from 12.5–23.7 GHz. This work has potential application in the field of the stealthy platform.Additional informationFundingThis work was supported by National Natural Science Foundation of China [62361004, 62161002, 62161003]; Natural Science Foundation of Guangxi Province [2021GXNSFDA220003, 2020GXNSFAA297018]; Guangxi Key Laboratory of Precision Navigation Technology and Application, Guilin University of Electronic Technology [DH202223]; National Key Research and Development Program of China [2021YFA0715404, 2022YFE0134600].