A Coding Metasurface With Properties of Absorption and Diffusion for RCS Reduction

Abstract

Abstract-A low-radar cross section (RCS) coding metasurface (MS) with properties of absorption and diffusion for both normal and oblique incidences is proposed in this paper. The coding MS is composed of a miniaturized perfect metamaterial absorber (PMA) and a wideband artificial magnetic conductor (AMC) in a shared aperture. In addition, to avoid strong scattering energy appearing at specific directions, genetic algorithm (GA) is adopted to search the optimal layout of the two MS elements. Simulated and experimental results confirm the properties of coding MS and indicate that the 6-dB RCS reduction bands under TE-and TM-polarized normal incident waves are 6.28 GHz-9.16 GHz and 6.33 GHz-9.41 GHz, respectively.

Passive techniques for target radar cross section reduction: A comprehensive review

“…These metasurfaces have been designed by arranging meta‐particles with different sizes or various orientations in a pattern such that a broadband and wide‐angle RCSR has been fulfilled. The diffusion metasurfaces 96‐144 can be categorized into different groups realizing and focusing on some interesting functions and applications of them, such as polarization conversion metasurfaces 79,81,85,87‐89 (discussed in Section 2.2), Mantle Cloaks, 139‐141 checkerboard metasurfaces based on phase cancelation, 101,137,138,144 coding and digital metasurfaces, 99,100,116‐118,120,121,126,129,131,134‐136,143 phase gradient metasurfaces, 103,104,115,142 and hybrid metasurfaces 100,107‐109,142 . Various arrangements of these metasurfaces were proposed to backscatter the incident waves to arbitrary areas away from the receiver direction.…”

“…Additionally, most of them have been performed only for monostatic RCSR at normal incident angle ignoring the wave polarization. Hence, nowadays, the modern passive techniques and structures based on phase cancelation or destructive interference using surfaces including frequency selective surface (FSS), 52‐55 EM band gap (EBG), 56‐59 artificial magnetic conductor (AMC), 47,48,60‐77 polarization rotation reflective surface (PRRS), 78‐95 metasurfaces, 96‐145 and hybrid methods, 146‐149 receive a lot of attention to improve the mentioned conventional techniques and overcome their limitations. In the recent decades, researchers have made a lot of efforts on these modern passive RCSR techniques and numerous works have been proposed and completed in order to achieve a system similar to the ideal RCSR system.…”

Machine-Learning-Powered EM-Based Framework for Efficient and Reliable Design of Low Scattering Metasurfaces

“…Therefore, it has been established that -10-dB RCS reduction can be maintained over a frequency band if the phase difference between the two AMC cells remains within the 143 • -217 • range (i.e., 180 • ± 37 • ) [24]. More recently, the concepts of coding metasurfaces [25], diffusion metasurfaces [26], [27], programmable metasurfaces [30], Huygens' metasurfaces [31], and cloaking structures [32] have been proposed, which offer a control over the wavefront in a more sophisticated manner. The primary advantage of coding and diffusion metasurfaces over the checkerboard type surfaces is that it scatters the incident EM waves into all directions.…”

Dual‐band reconfigurable metasurface‐assisted Fabry–Pérot antenna with high‐gain radiation and low scattering

“…To date, many approaches have been proposed for achieving RCS reduction [32–34]. Coding metasurface is capable of reducing RCS through phase cancellation technique to scatter the incident waves in multiple directions [31, 35–37]. By using this method, both monostatic and bistatic RCSs can be reduced effectively with an optimised coding sequence.…”