In this paper, a novel method of realizing the ultra-wideband (UWB) radar cross section (RCS) reduction is proposed. We combine the chessboard structure of multi-elements which are all polarization conversion metasurface (PCM) units with random coding. Four different kinds of PCM units all with UWB and much high polarization conversion rate (PCR) are selected. Morever, their polarization conversion frequency bands are optimized not only in the high frequency segment but also in the low frequency segment. The final designed structure can achieve 10 dB RCS reduction within 6.9 GHz-20.1 GHz in the high frequency segment and 15.5 GHz-51.2 GHz in the low frequency segment, respectively. In addition, the effects of RCS reduction by the square chessboard structure composed of different numbers of these PCM units are compared. The proposed metasurface structure provides an efficient scheme to reduce the scattering of the electromagnetic waves.

In this paper, a multilayer ultra-wideband transparent metamaterial wave absorber is proposed, which has the characteristics of ultra-wideband wave absorption, light transmission and flexible bending; in addition, due to the complete symmetry of the structure, the absorber has polarization insensitivity to incident electromagnetic waves. Both simulation and experimental results show that the frequency range of the microwave absorption rate is higher than 90% between 8.7 GHz and 38.9 GHz (between which most of the absorption rate can reach more than 95%), the total bandwidth is 30.2 GHz, and the relative bandwidth is 126.9%, realizing microwave broadband absorption and covering commonly used communication frequency bands such as X-band, Ku-band, and K-band. A sample was processed and tested. The test results are in good agreement with the results of the theoretical analysis, which proves the correctness of the theoretical analysis. In addition, through the selection and oxidation of indium tin (ITO) materials, the metamaterial also has the characteristics of optical transparency and flexibility, so it has potential application value in the window radar stealth and conformal radar stealth of weapons and equipment.

In this paper, a novel ultra-wide band (UWB) random 3-bit coding metasurface with polarization independence has been designed to realize radar cross-section (RCS) reduction. The proposed structure consists of polarization conversion metasurfaces (PCMs), which possess the capability of rotating linear polarization waves to their orthogonal ones in an UWB. The polarization-independent property can be attributed to the random rotation angle of each constituting unit. Due to the randomness of 3-bit coding and rotation angle of each element, the divergence of the reflected beam is greatly improved. In addition, the effect of RCS reduction with respect to the unit period length and the unit position are also discussed. Finally, a prototype is fabricated and measured to validate the simulation. The experimental results demonstrate that an ultra-wide band RCS reduction over 10 dB, ranging from 18.3–42.2 GHz, can be attained by the proposed coding metasurface and the maximum reduction is 28.7 dB.

Phase gradient metasurface (PGM) is capable of realising anomalous wave deflection, while focusing metasurface is widely adopted in converging electromagnetic (EM) waves through phase compensation. Here, a single‐layered focusing anisotropic metasurface (FAM) for dual‐band reflected beam steering is proposed. The anisotropic metasurface is composed of modified Jerusalem cross‐structures with which reflected waves can be focused and deflected simultaneously. Furthermore, the distributions of reflection phase required in two frequency bands can be controlled independently by adjusting the dimensions of the cells along two orthogonal directions. To verify the proposed structure, a prototype with a size of 260 × 260 mm is fabricated, assembled, and measured. Good performances have been achieved in both simulation and measurement results, which agree with theoretical predictions. The measured results indicate that reflected waves generated by the FAM can be deflected to −42° with a gain of 17.5 dBi and −30° with a gain of 20.5 dBi at 5.7 and 10 GHz, respectively.

With the rapid development of 5G communication technology, high-frequency electromagnetic interference (EMI) shielding plays a vital role in the normal operation of electrical and electronic equipment and systems, and has attracted surging interest in 5G mm-wave applications. However, many current EMI shielding materials contain highly conductive materials, resulting in strong secondary reflection and environmental pollution. Here, we propose a green high-performance EMI shielding material for 5G mm-wave based on a metamaterial absorber (MMA). Characteristic mode theory and equivalent circuit are employed to inversely design the unit cell’s dimension and structure, as well as the resistive value of the proposed MMA. We reveal that from 22 to 43.5 GHz, the shielding effectiveness of higher than 30 dB, and the standard green index of SE_R < 3.01 dB and g _s ⩾ 1 can be realized whether the MMA is flat or even bent. Excellent agreement between the measured and simulated results verified the high performance of the proposed EMI shielding MMA. The transmittance of over 85.84% can be achieved within the 380 ∼ 800 nm spectrum. The proposed green EMI shielding material integrates multi-functionalities of low profile, flexibility, polarization-insensitiveness, wide-angle, and optical transparency, and can find potential applications in EMI shielding in complex electromagnetic environments.