微带天线RCS减缩新技术研究

发布时间：2018-10-08 16:52

【摘要】：近年来,随着现代信息技术的快速发展,传统武器装备的战场生存力、突防能力受到日益严峻的挑战。为了有效降低这一威胁,低可见武器平台成为各国大力发展的新技术。对于低可见武器平台,天线系统作为一种特殊的散射体,往往会对整个平台的隐身性能产生严重的影响。尽管外形和加载吸波材料技术在一定程度上能够减缩天线RCS,但是会对天线的自身辐射产生影响。因此天线系统要保持良好的辐射性能,传统的RCS减缩技术就不能直接被用于其RCS减缩。如何在保证天线辐射性能的同时,尽可能多的减缩其RCS,已经成为制约整个系统隐身性能的瓶颈问题。本论文正是基于这种实际应用背景的需求,在保证不改变天线辐射结构的同时,通过新技术、新方法的应用达到减缩微带天线RCS的目的。具体来说,论文的主要内容可以概括为以下几个方面:1:天线作为一种特殊的散射体,其散射场包括结构模式项和天线模式项,因此其散射机理比较复杂。论文首先对天线的散射理论做了介绍,在此基础之上,总结了一些用于天线RCS减缩的常用方法。该散射理论为本论文后续有关天线RCS减缩的相关内容提供了坚实的理论基础。2:人造磁导体(artificial magnetic conductor-AMC)是近年来发展起来的一种新的人工材料。由于其独特的高阻抗特性,AMC被广泛运用于低剖面天线设计,天线RCS减缩等领域。作为一种谐振结构,AMC同样具有工作带宽较窄的特性,因此无法在较宽的频段范围内实现天线RCS减缩。为了解决这一问题,本论文中提出了混合AMC结构。通过合理的结合两种工作在不同频段的AMC单元,可以实现4-12GHz频带范围内的微带天线RCS减缩。3:相对于带外RCS减缩,天线带内RCS减缩更加困难。这是因为天线带内RCS和微带天线自身辐射性能息息相关。正是基于这种现实情况的考虑,论文中探索了利用微带谐振腔结构减缩微带阵列天线带内RCS的可能性。仿真和实测结果表明,该方法可以在很大程度上减缩微带天线带内RCS,同时保证微带天线的辐射性能不受明显的影响。与常规的带内RCS减缩方法相比,该方法具有结构简单的优势。4:梯度渐变表面(gradient-index metasurfaces)是近年来发展的一种新型的人工超材料。通过合理的设计该表面的相位特性,该材料可以表现出PW-SW转换和奇异反射等特性。论文中设计了一种耶路撒冷十字型梯度渐变表面,通过利用该结构的PW-SW转化和奇异反射特性,可以实现微带缝隙阵列天线6-18GHz频带范围内的宽带RCS减缩。相比于传统的天线RCS减缩技术,该方法可以同时实现天线带内和带外RCS减缩,并且对天线辐射性能基本上没有影响。
[Abstract]:In recent years, with the rapid development of modern information technology, the battlefield survivability and penetration ability of traditional weapons are increasingly challenged. In order to reduce this threat effectively, low-visible weapon platform has become a new technology developed by all countries. As a special scattering object, antenna system has a serious effect on the stealthy performance of the low visible weapon platform. Although the shape and loading of absorbing materials can reduce the antenna RCS, to some extent, it will have an effect on the antenna's own radiation. Therefore, in order to maintain good radiation performance of antenna system, the traditional RCS reduction technology can not be directly used for its RCS reduction. How to reduce the RCS, as much as possible while ensuring the radiation performance of the antenna has become a bottleneck problem that restricts the stealthy performance of the whole system. Based on the requirement of this practical application background, this paper guarantees that the radiation structure of the antenna will not be changed, and at the same time, the purpose of reducing the RCS of the microstrip antenna can be achieved by the new technology and the application of the new method. Specifically, the main contents of this paper can be summarized as follows: as a special scattering object, the scattering field of antenna consists of structural mode term and antenna mode term, so the scattering mechanism is quite complex. Firstly, the scattering theory of antenna is introduced, and then some common methods for antenna RCS reduction are summarized. The scattering theory provides a solid theoretical basis for the related contents of antenna RCS reduction in this paper. The artificial magnetic conductor (artificial magnetic conductor-AMC) is a new artificial material developed in recent years. Because of its unique high impedance characteristics, AMC is widely used in low profile antenna design, antenna RCS reduction and other fields. As a kind of resonant structure, the antenna RCS can not be reduced in a wide frequency range because of its narrow bandwidth. In order to solve this problem, a hybrid AMC structure is proposed in this paper. By reasonably combining two kinds of AMC elements working in different frequency bands, the RCS reduction of microstrip antenna in the range of 4-12GHz band can be realized. 3. Compared with out-of-band RCS reduction, it is more difficult to reduce RCS in the antenna band. This is because the RCS in the antenna band is closely related to the radiation performance of the microstrip antenna itself. Based on this practical situation, the possibility of reducing the RCS in the microstrip array antenna by using the microstrip resonator structure is explored in this paper. The simulation and experimental results show that the proposed method can greatly reduce the RCS, in the microstrip antenna and ensure that the radiation performance of the microstrip antenna is not obviously affected. Compared with the conventional in-band RCS reduction method, this method has the advantages of simple structure. 4: gradient surface (gradient-index metasurfaces) is a new type of artificial supermaterial developed in recent years. By reasonably designing the phase characteristics of the surface, the material can exhibit PW-SW conversion and singular reflection characteristics. In this paper, a Jerusalem cross gradient surface is designed. By using the PW-SW transformation and singular reflection characteristics of the structure, wideband RCS reduction can be realized in the 6-18GHz band range of the microstrip slot array antenna. Compared with the traditional antenna RCS reduction technique, this method can reduce the antenna RCS in and out of the band at the same time, and has no effect on the antenna radiation performance.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN822

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