【作者】 张倩；

【导师】 刘运林；

【作者基本信息】 西南交通大学 ， 电磁场与微波技术， 2012， 硕士

【摘要】 天线是现代无线通信系统重要的前端器件,而微带天线因其一系列优点,受到了广泛的关注。随着越来越高的性能要求,微带天线阵在一些领域比单一的微带天线更能显出优势,而微带天线阵的性能因受阵元之间互耦的影响并不是简单的单一微带天线的叠加。天线阵列的复杂性使其设计优化方法需要耗费大量的人力物力和时间,因此对微带天线阵列实现快捷准确的分析优化,是当下国内外对天线进行科研的专家和学者们的热点关注问题。John W. Bandler等人构想出的空间映射算法的根本思想是尝试在粗糙模型和精确模型的两个参数空间之间,搭建一种映射关系,然后以迭代的方式来更新和改进粗糙模型,随着数据的累积,使替代模型响应拟合于精确模型响应,最终达到误差范围内的一致,以此来代换精确模型的高成本计算。该算法的特点是高效率高精度。本文首先介绍了微带天线和空间映射算法的基本概念,发展历程以及分析方法等。然后应用空间映射算法的思想,通过对微带天线平面阵列的远区辐射方向图性能的考察,研究了微带天线阵列阵元之间的互耦效应。文章先结合平面天线基本理论和端口网络理论,对平面天线的远区辐射方向图进行了分析,并提出了相应的数学表达式。然后在高频电磁仿真软件HFSS的帮助下获取平面天线阵列阵元之间的互耦系数,应用空间映射算法的思想,建立了平面天线阵的粗糙模型和精确模型,其中粗糙模型是不考虑阵元之间的互耦效应的,其分析精确度低而计算速度快计算效率高,而精确模型是考虑互耦效应的全阵元模型,其分析精确度高而计算速度慢计算效率低。其后结合MATLAB软件进行编程计算。文章先通过计算规模为3*3的微带天线平面阵列,讨论了其阵元之间的互耦效应在其远区辐射方向图中的影响,成功的拟合了其精确模型结果,之后在规模为5*5的微带天线平面阵列中,进行了讨论和验证。文章通过这两个阵列的数值分析验证了该方法的可靠性,说明了空间映射算法结合粗糙模型高效和精确模型高准确度的有效性,为大型天线阵列的优化分析提供了较为有价值的参考。更多还原

【Abstract】 Antennas are the important front-end devices of modern wireless communication system. Because of a series of advantages, microstrip antennas attract more and more attention. With the increasingly high performance requirements, the microstrip antenna array show more advantages than a single microstrip antenna in some areas. While the performance of microstrip antenna array is not a simple superposition of the single antenna, because the mutual coupling effects between its elements have a great impact on the performance of the overall array. And the complexity of the mutual coupling effects requires a lot of effort and time-consuming in some design optimization methods of the antenna array, so the fast and accurate analysis and optimization for the microstrip antenna array has become the domestic and foreign scholars’research priorities. The space mapping algorithm proposed by John. W. Bandler. The basic idea of the space mapping algorithm is first establishing a mapping between the two parameter space of the coarse model and the fine model, then using the iterative calculation and updating the coarse model instead of the fine model which has a high cost of calculation. With the accumulation of data, the coarse model response will gradually close to the fine model response,and ultimately achieve consistent within the error range. The advantages of this algorithm are high-efficiency and high-precision.This paper first introduces the basic concepts and the development of the microstrip antenna, and the basic concepts of the space mapping algorithm. Then the mutual coupling effect in far-field radiation pattern of planar antenna array is studied by using space mapping algorithm idea. In the paper, the far-field radiation pattern of planar antenna array is analysed by the basic theory of planar antenna array and the port network theory, and has derived the corresponding formulas. First we establish the coarse model without considering the mutual coupling effects between the elements, which has high computational efficiency but low accuracy, and the fine model, the whole array element model considering the mutual coupling effect, which has high accuracy but low computational efficiency. Then we study the mutual coupling effect in depth by matlab programming and parameter extraction using HFSS with the aid of the principle of space mapping first based on a3*3planar array of rectangular microstrip antenna and then a5*5planar array. Through these two examples, the reliability of this method and the effectiveness of combining of the efficient in the coarse model and the accurate in fine model are verified, which have a good reference value for the optimization analysis of the large antenna array.更多还原