漏泄波导与漏波天线辐射特性研究

发布时间：2018-08-19 11:35

【摘要】：漏泄波导与漏波天线已在无线通信系统中得到了广泛应用。近年来,随着人们对无线通信要求的不断提高,以及基于无线通信列车自动控制系统的发展,受限空间高效电波覆盖问题受到重视,作为受限空间主要电波覆盖手段的漏泄波导与漏波天线也因此成为研究重点。本文旨在研究适用于受限空间的具有高效电波覆盖特性的新型漏泄波导与漏波天线,主要进行新型漏泄波导辐射特性分析、结构设计、以及应用中的环境适应性研究；同时在漏泄波导基础上研究适用于受限空间的圆极化漏波天线。研究工作对提高受限空间中的电波覆盖性能,进而提升无线通信可靠性具有重要意义。 本文的主要工作和创新成果如下： 1.设计了一种漏泄圆波导结构,以便在高频段代替漏泄同轴电缆、降低系统的传输损耗。在漏泄同轴电缆理论基础上,进行了漏泄圆波导的辐射模式及远场特性分析,给出了耦合损耗与结构参数的关系。结果表明,漏泄圆波导除了存在m0次空间谐波辐射外,也可以存在m≥0次空间谐波辐射,这是与漏泄同轴电缆不同的地方。 2.提出了一种利用全波数值结果求解漏泄圆波导传播常数的方法,分析了漏泄圆波导归一化传播常数随波导参数的变化关系。在此基础上,利用曲线拟合方法给出了漏泄圆波导传播常数的经验公式,为快速估算漏泄圆波导的传播常数、截止波长和辐射模式提供了一种方便有效的方法。 3.提出了一种加脊漏泄圆波导结构,通过沿波导轴线方向加细金属线的方法使得波导内场结构的极化方向保持不变,从而可以改善漏泄圆波导的长距离传输特性。此外,针对复杂通信环境对同一波导不同地方耦合量变化的要求,提出了一种贴片漏泄圆波导结构,可以通过改变附着在波导壁上金属贴片的尺寸和周期,在安装后灵活调整漏泄圆波导不同地方的耦合损耗,从而克服了漏泄圆波导耦合损耗因结构固定而无法改变的局限性。 4.以雪覆盖为例,研究了外界环境对漏泄波导辐射特性的影响,提出了一种在漏泄波导周围覆盖一层泡沫塑料层以降低环境影响的方法。研究表明,该方法可以有效降低积雪对波导辐射特性的影响。此外,针对仅工作在漏泄波导近距离处的通信系统,提出了通过在波导表面添加介质层来增强漏泄波导近距离处场强的方法,使漏泄波导的辐射能量能够聚焦到所需要的方向。 5.基于基片集成波导提出了一种N型缝隙圆极化漏波天线,并进行了加工测试。计算和实验结果表明,通过选择合适的缝隙结构和基片集成波导的基板参数,该N型缝隙漏波天线能够在8GHz频段和5.8GHz ISM频段实现圆极化辐射。
[Abstract]:Leaky waveguides and leaky antennas have been widely used in wireless communication systems. In recent years, with the increasing demand for wireless communication and the development of automatic train control system based on wireless communication, the problem of efficient radio coverage in restricted space has been paid more attention. Therefore, leakage waveguides and leaky antennas, which are the main means of radio coverage in confined space, have become the focus of research. The purpose of this paper is to study a new type of leaky waveguide and leaky antenna which is suitable for the confined space with high efficiency radio wave coverage. The radiation characteristics of the new leaky waveguide are analyzed, the structure design and the environmental adaptability of the application are studied. At the same time, the circular polarization leaky wave antenna suitable for confined space is studied on the basis of leaky waveguide. The research work is of great significance to improve the radio coverage performance in restricted space and improve the reliability of wireless communication. The main work and innovative results of this paper are as follows: 1. A leakage circular waveguide structure is designed to replace leakage coaxial cable in high frequency band and reduce the transmission loss of the system. Based on the theory of leakage coaxial cable, the radiation mode and far-field characteristics of leaky circular waveguide are analyzed, and the relationship between coupling loss and structural parameters is given. The results show that there is not only the space harmonic radiation of m 0 order, but also the space harmonic radiation of m 鈮，

本文编号：2191536