- 标题
- 摘要
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- 实验方案
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RCS Reduction and Gain Enhancement for the Circularly Polarized Array by Polarization Conversion Metasurface Coating
摘要： High-gain, the ultra-wide band circularly polarized (CP) array with low radar cross section (RCS) is proposed based on (UWB) polarization conversion metasurface (PCM) coating. A chessboard-like coating is formed by a mess of arrow-shaped PCM elements which have UWB and high polarization conversion ratio. The coating is distributed beneath the dipoles and behaving as a reflector. With the PCM beneath each dipole, the CP radiation is achieved and enhanced in a low profile by the radiating wave and the reflected wave, which have equal amplitude and 90° phase difference. With the chessboard-like coating, the incident wave is converted into the equal amplitude and out-of-phase reflected waves, which will cancel each other to reduce the backward scattering. The performances of the array are validated by both simulations and measurements. The results show that the left-hand CP radiation is achieved in 11.25 GHz to 12.31 GHz with the RCS being reduced for more than 4.8 dB in 10.5 GHz to 35.1 GHz.
关键词： high gain,circular polarization,low profile,radar cross section (RCS),polarization conversion metasurface (PCM)
更新于2025-09-09 09:28:46
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Reconfigurable metasurface for multiple functions: magnitude, polarization and phase modulation
摘要： A novel reconfigurable metasurface for multiple functions is designed and investigated. The lattice of the metasurface is proposed to realize integrated absorption and polarization rotation and named as polarization conversion absorber (PCA). Then, lattices are arranged together to realize a certain function. Due to the independence of each lattice, the metasurface can present different performance based on different arrangement principle. Magnitude, polarization and phase modulation can be presented by manually arranging metasurface with 6 × 6 lattices. Both simulations and measurements prove that the proposed method provides a simple, flexible and effective strategy for multifunctional metasurface design.
关键词： phase modulation,magnitude modulation,polarization modulation,reconfigurable metasurface,polarization conversion absorber
更新于2025-09-09 09:28:46
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Dual-patch Polarization Conversion Metasurface-based Wideband Circular Polarization Slot Antenna
摘要： In this letter, a novel polarization conversion (PC) structure is introduced, and its use with a wideband, wide 3-dB axial-ratio (AR) beam, low-radar-cross-section (RCS) circular polarization (CP) slot antenna is suggested. The unit cell of the proposed PC metasurface (PCM) consists of square and L-shaped patches separated by an L-shaped slot printed on an FR4 substrate. The mechanisms for linear to circular polarization and bandwidth improvement of a conventional antenna are analyzed theoretically. Through numerical optimizations and parametric studies, a simulated 10-dB impedance bandwidth of 42.7% (4.15-6.4 GHz) and a 3-dB AR bandwidth of 26.2% (4.8-6.25 GHz) are achieved by the proposed antenna. As the simulation demonstrates, the proposed antenna achieves an average 20-dB RCS reduction in a wide band from 5.25 to 6.8 GHz compared to a conventional slot antenna covered by the PC band. In addition, compared to previously reported work, the PCM-based CP antenna exhibits a larger 3-dB AR beam width of 200° in the xoz plane and 120° in the yoz plane, and a wider CP bandwidth within the operational bandwidth. Finally, an overall volume of 0.55λ0×0.55λ0×0.05λ0 centered at 5.275 GHz is fabricated and measured, demonstrating good agreement with the simulation results.
关键词： circularly polarized,low RCS,polarization conversion metasurface,dual-patch
更新于2025-09-09 09:28:46
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Nonreciprocal Optical and Magnetooptical Effects in Semiconductor Quantum Wells
摘要： Effects implying violation of the Fresnel light reflection laws in semiconductor structures with quantum wells (QWs) have been investigated. This violation is related to the manifestation of spatial dispersion caused by spin–orbit coupling in structures without inversion centers. The spin–orbit coupling constants characterizing polarization conversion in symmetric and asymmetric structures with QWs have been measured.
关键词： spatial dispersion,nonreciprocal optical effects,polarization conversion,spin–orbit coupling,semiconductor quantum wells,magnetooptical effects
更新于2025-09-09 09:28:46
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Comment on “A Broadband Terahertz Metamaterial Absorber Based on Two Circular Split Rings”
摘要： In a published report, Pan et al. presented a broadband terahertz metamaterial absorber（BTMA）to obtain a broadband absorption with a stability at the wide angle of incidence. In this article, we discover that the absorption rate of the proposed absorber is wrongly calculated because of the negligence of the cross-polarization reflection component. In fact, the absorption peaks are only 30.12% and 50.72% at 0.85 THz and 1.93 THz, respectively. The researchers proposed an absorber with poor performance.
关键词： Polarization conversion,Absorber,Metamaterial
更新于2025-09-09 09:28:46
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POLARIZATION TRANSFORMATION BY A HYPERBOLIC METAMATERIAL ON A METAL SUBSTRATE
摘要： In the present paper we focus on the study of polarization properties of biaxial metamaterial, which consist of alternate ferrite and semiconductor layers, located on an ideally conducted metal substrate. The system is placed into an external magnetic field along the boundaries of the layers. The effective medium theory is applied. Effective linear-to-elliptic polarization conversion has been shown, by means of physical and geometrical parameters of the system under consideration.
关键词： biaxial metamaterial,ferrite,linear-to-elliptic polarization conversion,metal substrate,polarization properties,semiconductor layers,external magnetic field,effective medium theory
更新于2025-09-04 15:30:14