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角反射器结构对入射电磁波有很强的反射能力,装备平台上一些不可避免的角结构会导致较大的雷达散射截面（radar cross section,RCS）,不利于装备隐身和生存. 为实现角反射器结构的隐身设计,本文提出一种基于相位对消超表面的二面角反射器（dihedral corner reflector, DCR）的单站RCS减缩方法. 论文首先分析了采用相位对消超表面实现DCR RCS减缩的基本原理,然后设计了两种超表面单元,反射相位差180°±37°的相位对消频带为7.6～17.6 GHz. 两种超表面单元交错排布组成棋盘结构的相位对消超表面,能够减小宽带范围内平面结构的镜像方向双站RCS. 用相位对消超表面替换DCR其中的一个侧面,在不改变反射器外形条件下,在整个X和Ku波段单站RCS实现了减缩,最大RCS减缩达到29.5 dB. 仿真分析和测试结果均验证了采用相位对消超表面实现对DCR宽带RCS减缩的有效性. 相似文献
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电磁超表面是一种新型的人工电磁材料,其在无线通信、信号处理等方面展现出了巨大的优势。电磁超表面通过引入外部激励(机械激励、热激励、电激励、光激励、磁激励等方式)实现了对电磁响应更为灵活的动态控制。基于动态调控的方式,电磁超表面能够实现对电磁波的相位、振幅、极化方式、传播模式等特性的精确控制,从而在不同的应用场景中实现波前调控。该文首先归纳总结了电磁超表面动态调控技术的研究进展;然后,讨论了电磁超表面在全息成像、极化转换、超构透镜、波束调控以及智能系统等领域中的研究现状;最后以调控技术为基石总结展望了电磁超表面的发展模式及未来智能化调控的发展趋势。 相似文献
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In this article, a coding optimized metasurface is proposed for linear polarization conversion in broadband and wide‐angle. Using an improved coding method, the geometry of the metallic structure and the size of the unit cell are encoded with a code sequence. The code sequence is optimized by genetic algorithm, considering bandwidth, efficiency, and angular stability. In this way, a coding optimized metasurface was obtained for polarization conversion in broadband and wide‐angle. It can convert linear polarized incidence to its orthogonal polarized reflection in 8 to 18.9 GHz and 0° to 45°, with the polarization conversion ratio larger than 80%. Both simulated and measured results demonstrated the effectiveness of the proposed metasurface. Hence, our method offers an effective strategy to design high‐performance polarization conversion metasurfaces. 相似文献
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Ruipeng Liu Xia Wang Dong Nie Lu Wang Wenjie Cui Mengjun Wang Hongxing Zheng Erping Li 《国际射频与微波计算机辅助工程杂志》2020,30(2)
The metasurface technique has been applied to enhancing the gain and directivity of antenna in this paper. The normal metal ground is replaced by one metasurface structure to suppress the higher frequency component transmission. Another similar metasurface structure is put nearer to the antenna to increase gain and enhance directivity further. A low‐pass filter with defected ground plane is designed to obtain steeper falling edges and a wider stop band. Then a rectifier circuit is designed for the electromagnetic energy of input terminal converted into a DC output. The three parts of passive circuit make up a complete energy receiving system. The measured results of the system shown that the output voltage stable. 相似文献
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Yuan Liu Yu‐Xuan Huang Zhan‐Wei Liu Shu‐Ting Cai Xiao‐Ming Xiong Jing Guo 《国际射频与微波计算机辅助工程杂志》2020,30(7)
In this article, a new low‐profile broadband circularly polarized antenna with a single‐layer metasurface is designed. The metasurface is composed of 4 × 4 rotated rectangle‐loops. Compared to single rotated rectangle, introducing inner‐cut rectangle slot can increase the design flexibilities by changing this slot size for wider circularly polarized operating bandwidth and reduce the size of the antenna in same frequency. The proposed antenna has the advantages of a wide 3‐dB axial ratio bandwidth from 5.4 to 6.05 GHz and an excellent 10‐dB impedance bandwidth from 5 to 6.05 GHz. 相似文献
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A single‐layer transmitting focusing gradient metasurface (F‐GMS) has been proposed that can realize high gain increment at 10 GHz. The unit of F‐GMS is composed of two identical structures placed on the top and bottom of one dielectric layer, which can have high transmitting efficiencies that over 0.8 and achieve [0, 2π] phase range in X‐band. The F‐GMS can convert the spherical waves into plane waves. A patch antenna working at 10 GHz is positioned as the focus of the proposed F‐GMS as the feed source to develop an ultrathin flat lens antenna system. It achieves a simulated gain of 19.6 dBi which is 12.9 dB greater than that of the single patch antenna at 10 GHz. Lastly, the F‐GMS and the patch antenna are manufactured and then measured in an anechoic chamber. A good agreement was demonstrated between experimental and simulated results. 相似文献
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A broadband double‐layer transmissive metasurface (TMS) for effective generate vortex electromagnetic wave is presented in this paper. The proposed TMS consists of two types of elements. The first element is composed of a multi‐resonant dipole and four metal vias. The metal vias increase the coupling strength between the upper and lower layers to improve transmission efficiency. On the basis of the first element, the second element adds stubs to ensure sufficient phase shift. The far‐field cross polarisation is eliminated by special element arrangement. Then, a centre‐fed linear polarisation TMS is designed to generate orbital angular momentum beams with mode l = ? 1. The proposed TMS is designed, manufactured and measured to verify the proposed design. The measured results indicate that a maximum gain of 20.8 dBi and narrow divergence angle of ±5° are achieved at 18 GHz. Furthermore, mode purity is higher than 86.1% within the 17 to 19 GHz band. The proposed double‐layer TMS saved costs, reduced weight and without assembly error is a good candidate for OAM generator. 相似文献
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为解决当前太赫兹频段下的极化转换器件带宽窄和带内转换率低的问题,设计了一款基于超表面的高效率太赫兹线极化转换器.通过在两端增加一对谐振枝节的方法,将原本的单谐振频点变为2个,增加了极化转换器的工作带宽.另一方面,利用超表面在电磁谐振时的高阻抗表面特性,获得了极低的同极化反射系数,提高了带内的总体转换效率.仿真结果显示,... 相似文献
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