低散射人工电磁表面的散射特性研究

发布时间：2018-05-05 04:35

本文选题：微波段 + 太赫兹波段　；参考：《东南大学》2015年硕士论文

【摘要】：基于漫反射原理的低散射人工电磁表面由大量具有随机相位分布的亚波长单元构成。当电磁波入射到该电磁表面时,其能量将分布在各个方向中。通过合理地设计表面单元的几何结构和排布方式,可以有效地降低所覆盖金属目标的后向散射截面,对于隐身表面设计具有重要的意义。本文的主要工作包括以下几个方面：(1)设计了微波段单层宽带低散射人工电磁表面,与多层结构相比,单层人工电磁表面在空间分布上更加紧凑,易于加工,更适合共形方面的应用。设计的单层低散射人工电磁表面单元的移相范围在360°以上,且反射相位与单元的尺寸满足线性变化关系。将该单层低散射人工电磁表面覆盖在目标表面上,电磁波照射到低散射人工电磁表面后向各个方向散射。与反射阵的高定向散射方向图不同,低散射人工电磁表面的散射能量分布在各个方向上,有效降低了目标被雷达探测到的概率。(2)将微波段低散射人工电磁表面的设计方法拓展到了太赫兹波段,提出了太赫兹单层低散射人工电磁表面。由于太赫兹加工工艺的限制,为了在整个波段内获得较大的相移范围,设计的低散射人工电磁表面采用了两种亚波长微带单元,这两种单元都由内环和外环组成。设计的两种单元的形状关于x轴方向和y轴方向是轴对称的,具有极化不敏感的特点。该太赫兹低散射人工电磁表面具有较低的散射系数,有效地隐匿了目标。
[Abstract]:The low scattering artificial electromagnetic surface based on diffuse reflection principle is composed of a large number of subwavelength units with random phase distribution. When the electromagnetic wave is incident to the electromagnetic surface, its energy will be distributed in all directions. By reasonably designing the geometry and arrangement of the surface elements, the backscattering cross section of the covered metal target can be effectively reduced, which is of great significance for the design of the stealth surface. The main work of this paper includes the following aspects: (1) the monolayer wideband low scattering artificial electromagnetic surface of microwave section is designed. Compared with the multilayer structure, the monolayer artificial electromagnetic surface is more compact in spatial distribution and easy to process. More suitable for conformal applications. The phase shift range of the single layer low scattering artificial electromagnetic surface element is more than 360 掳, and the reflection phase and the size of the element are linearly varying. The monolayer artificial electromagnetic surface is covered on the target surface and the electromagnetic wave is radiated to the low scattering artificial electromagnetic surface and scattered in all directions. Different from the high directional scattering pattern of the reflection array, the scattering energy of the low scattering artificial electromagnetic surface is distributed in all directions. The probability of target detected by radar is reduced effectively. The design method of microwave band low scattering artificial electromagnetic surface is extended to terahertz band, and a terahertz monolayer low scattering artificial electromagnetic surface is proposed. Due to the limitation of terahertz processing technology, in order to obtain a large phase-shift range in the whole band, two kinds of sub-wavelength microstrip elements are used in the design of the low scattering artificial electromagnetic surface, both of which are composed of inner and outer loops. The shapes of the two elements are axisymmetric and polarization-insensitive with respect to the x axis and y axis directions. The terahertz low scattering artificial electromagnetic surface has low scattering coefficient, which effectively hides the target.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN011

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