Deterministic Approach to Achieve Broadband Polarization-Independent Diffusive Scatterings Based on Metasurfaces

Abstract

Diffusive scatterings of electromagnetic (EM) waves by a thin screen are important in many applications, but available approaches cannot ensure uniform angular distributions of low-intensity scatterings without time-consuming optimizations. Here, we propose a robust and deterministic approach to design metasurfaces to achieve polarization-independent diffusive scatterings of EM waves within an ultrabroad frequency band and for wide-range of incident angles. Our key idea is to use high-efficiency Pancharatnam−Berry meta-atoms to form subarrays exhibiting focusing reflection-phase profiles, that can guarantee nearly uniform diffusive scatterings for arbitrarily polarized EM waves. As an illustration, we design and fabricate two metasurfaces and experimentally characterize their wave-diffusion properties in C, X, and Ku bands. Theoretical, numerical and experimental results demonstrate that our approach can diffuse the incident energy much more uniformly than available approaches based on the uniform-phase subarrays, thanks to the intrinsic wave-diffusion capabilities of the focusing-phase subarrays. The −7 dB fractional bandwidth is measured as 88.3% and the diffusive scattering behavior can be preserved up to 60°off-normal incidence irrespective of incident polarizations. Our approach, simple and robust, can help realize stealth applications under bistatic detections.

High gain transmitarray antenna based on ultra‐thin metasurface

“…In recent years, metasurface (MS) are getting more and more attention and finding its application in many fields because of its flexibility and manufacturing convenience . Compared with bulk metamaterial, the MS shows significant advantages in both microwave and optical frequencies, such as less loss, smaller dimensions, easier to assemblage, and so on.…”

Broadband RCS reduction in microstrip patch antenna using L-shape stepped polarization rotation reflective surface

“…Apart from this, in order to achieve broadband RCS reduction combined AMCs with 180° phase difference is utilized, which makes the design complex . Also, several scattering approaches based on metasurfaces are utilized in current stealth technologies . They reduce the RCS better than −5 dB even when the incidence angle is up to 60°.…”

An efficient reflective polarization rotation meta surface for broadband RCS reduction

“…But as the incident angle (θ) increases, the −3 dB bandwidth of the reflection coefficient reduces. Scattering approaches like deterministic diffusive scattering and diffusive invisibility techniques are utilized in current stealth technologies to reduce the RCS better than −5 dB up to an incidence angle of 60° . In contrast, a highly efficient low profile broadband RCS reduction can be realized with the proposed configuration, by maintaining a −3 dB bandwidth of the reflection coefficient even on increasing the incident angle (θ).…”