In this paper, we propose an ultrabroadband chiral metasurface (CMS) composed of S-shaped resonator structures situated between two twisted subwavelength gratings and dielectric substrate. This innovative structure enables ultrabroadband and high-efficiency linear polarization (LP) conversion, as well as asymmetric transmission (AT) effect in the microwave region. The enhanced interference effect of the Fabry–Perot-like resonance cavity greatly expands the bandwidth and efficiency of LP conversion and AT effect. Through numerical simulations, it has been revealed that the cross-polarization transmission coefficients for normal forward (-z) and backward (+z) incidence exceed 0.8 in the frequency range of 4.13 to 17.34 GHz, accompanied by a polarization conversion ratio of over 99%. Furthermore, our microwave experimental results validate the consistency among simulation, theory, and measurement. Additionally, we elucidate the distinct characteristics of ultrabroadband LP conversion and significant AT effect through analysis of polarization azimuth rotation and ellipticity angles, total transmittance, AT coefficient, and electric field distribution. The proposed CMS structure shows excellent polarization conversion properties via AT effect and has potential applications in areas such as radar, remote sensing, and satellite communication.

本文提出了一种基于二氧化钒（VO₂）相变特性的开口谐振环结构多功能超材料器件。该器件由VO₂填充的开口谐振环和中心放置十字的顶层、聚酰亚胺（PI）介质层和金属基底构成。VO₂在绝缘态时，可以实现交叉极化转换功能，在0.48~0.87 THz范围内，偏振转换率大于90%。当VO₂为金属态时，该器件能够实现双频吸收和高灵敏度传感功能。在1.64 THz和2.15 THz频率处的吸收率大于88%。通过改变样品材料的折射率，两个频率点处的传感灵敏度分别约为25.6 GHz/RIU和159 GHz/RIU，品质因子Q分别为71.34和23.12。所提出的超材料多功能器件具有结构简单、可切换功能和高效率极化转换等特性，在未来太赫兹通信、成像等领域都有潜在的应用价值。

Phase-modulated metasurfaces that can implement the independent manipulation of co- and cross-polarized output waves under circularly polarized (CP) incidence have been proposed. With this, we introduce one particular metasurface composed of meta-atoms with a phase difference of 2π/3 to generate specific elliptically polarized waves under various polarized incidences. Furthermore, a metasurface composed of these above meta-atoms and the meta-atoms with a phase difference of π/3 arranged in a certain rule can realize polarization conversion function between linearly polarized and CP states. The designs shed new light on multifarious optical devices and may further promote the development of metasurface polarization optics.

为了实现天线罩的轻量化，同时满足高功率的应用，提出了一种高功率内置弧形折线栅式极化转换天线罩。该天线罩将弧形折线栅式极化转换板放置于介质密封罩内部，通过对弧形折线栅单元结构及介质密封罩结构的联合设计，在实现轻量化的同时降低了金属栅上的电场，使其更加有利于在高功率微波领域的工程应用。针对C波段高功率线极化螺旋阵列天线的应用需求，优化设计了一个中心频率为4.3 GHz的高功率极化转换天线罩，将其加载至某高功率径向线螺旋阵列天线上开展了辐射特性和功率容量的仿真和测试，仿真和实验结果吻合，该天线罩可实现圆极化波到线极化波的转换，其中心频率下的插入损耗为0.2 dB，主射方向轴比为20 dB，功率容量达到48 MW。