Hybrid-phase approach to achieve broadband monostatic/bistatic RCS reduction based on metasurfaces

Abstract

In this paper, we propose an approach to design metasurfaces to realize superior performance for monostatic and bistatic radar cross section (RCS) reduction within a wide bandwidth. By engineering four subarrays to exhibit different hybrid focusing-linear phases within a metasurface, nearly uniform diffusive scattering can be inherently guaranteed. As an illustration, we design and fabricate a proof-of-prototype metasurface and experimentally demonstrate its wave-diffusion performances. Numerical and experimental results both show that the thin metasurface enables a monostatic/bistatic 10 dB RCS reduction over a broad bandwidth ranging from 7.2 to 17.2 GHz. In addition, more than 10 dB RCS reduction performance is preserved within a band of 7.8 ∼ 14.2 GHz even for off-normal incidence up to 60°. Our approach features broadband, polarization insensitive, wide incident angles and easy design without time-consuming optimization, promising great potentials in applications of low-scattering stealth.

Wideband Radar-Cross-Section Reduction Using Parabolic Phased Metasurfaces

“…The Metasurfaces designed using only full parabolic phase profiles across their apertures suffer from narrow RCS reduction bandwidth and narrow scattering angle [27]- [30]. In this work, an efficient and fast design approach is proposed based on adding the parameter N (N = 1, 2, 3, 4, 5 …etc) to the original parabolic phase equation and the modified formula becomes equation ( 1).…”

“…Parabolic phase distribution is extensively used in the literature to design high gain antennas such as focusing lenses [23] and reflectarrays [24]- [26]. As shown in [27]- [30], metasurfaces with parabolic phase distribution across their apertures can be used for both monostatic and bistatic RCS reduction due to their intrinsic diffusive scattering features. However, it was shown in [27]- [30] that a full parabolic phased metasurface has some drawbacks such as narrow bandwidth and scattering patterns of narrow scattering angles.…”

“…As shown in [27]- [30], metasurfaces with parabolic phase distribution across their apertures can be used for both monostatic and bistatic RCS reduction due to their intrinsic diffusive scattering features. However, it was shown in [27]- [30] that a full parabolic phased metasurface has some drawbacks such as narrow bandwidth and scattering patterns of narrow scattering angles. To overcome these drawbacks, the researchers in [27] have divided the metasurface into a number of subarrays to exhibit non-similar parabolic phase profiles and distributed randomly across the metasurface aperture.…”

“…To overcome these drawbacks, the researchers in [27] have divided the metasurface into a number of subarrays to exhibit non-similar parabolic phase profiles and distributed randomly across the metasurface aperture. In [30], the metasurface was divided into four subarrays exhibiting hybrid-phase constructed by combining the focusing parabolic phase with 1D linear phase gradients. In [29], a chessboard-like phase profile was combined with parabolic phased subarrays of random focal lengths ay each unit cell.…”

Heterogeneous Amplitude−Phase Metasurface for Distinct Wavefront Manipulation

“…[1][2][3][4][5][6] With their constituent subwavelength meta-atoms arranged over a 2D plane, metasurfaces are able to impart arbitrary wavefront manipulation for any EM wave. [7][8][9][10] Currently, metasurfaces are used in an array of applications including imaging and hologram, [11] vortex beam generation, [12] radar-cross section (RCS) reduction, [13][14][15][16] ultrathin cloak, [17,18] polarization manipulation, [19][20][21] information encoding, [22] and many other advanced functionalities. [23][24][25] Although excellent wavefront manipulation can be achieved by controlling phase, conventional implementations of gradient metasurfaces are typically narrow band and cannot sustain their performance over practical spectral bandwidth.…”