【作者】 赵宇宁；

【导师】 杨晓冬；

【作者基本信息】 哈尔滨工程大学 ， 电磁场与微波技术， 2008， 硕士

【摘要】 泄漏同轴电缆具有信号覆盖均匀、低耦合损耗、容易安装和改变通信线路、很少污染环境等优点,在许多无线通信无法实现的场合或外界传播条件非常恶劣的情况下,泄漏同轴电缆仍可实现自由通信。因此,它被广泛地应用在诸如地铁、隧道、地下商场、矿井等闭或半闭域空间移动通信,具有广泛的应用前景。本文首先对泄漏同轴电缆的发展及其相关的基本知识做了简要阐述,介绍了泄漏同轴电缆的物理结构、分类以及与其相关的几个重要的电特性参数,并且根据泄漏同轴电缆结构进行了辐射原理的探讨,分析了其辐射模式,运用柱面傅里叶变换由外导体上的开槽处的场分布得到泄漏同轴电缆在自由空间的辐射场。然后,对泄漏同轴电缆的重要的电气特性指标耦合损耗的测量方法与计算方法进行了详细的分析,讨论了耦合损耗的影响因素,对耦合损耗理论值的进一步优化提出了改进办法,并对耦合损耗和辐射损耗的关系作了进一步的探讨。最后,分析了泄漏同轴电缆在闭域空间中的耦合损耗,用几何光学和波导模式匹配等方法详细推导了垂直开槽和倾斜开槽结构的泄漏同轴电缆在矩形和圆形的隧道中以及屏蔽良好的矩形室内空间中的耦合损耗表达式,并讨论了影响隧道中泄漏同轴电缆耦合损耗的外部因素。更多还原

【Abstract】 Leaky coaxial cable has many advantages such as homogeneously wide coverage, low coupling loss, easily assembled and changed communication circuits, fewer pollution, and so on. When it’s difficult to communicate in wireless communication or the external propagation condition is in very bad situation, the leaky coaxial cable can still work well. Leaky coaxial cable is widely used in confined areas such as subways, tunnels, underground markets, mines, and other buildings in blind or semi-blind zones, so it has broad applied prospect.At first, this paper briefly introduced the development and basic knowledge of leaky coaxial cable, and then explained the physical configuration, category and several related important electric parameters of leaky coaxial cable. According to the structure of leaky coaxial cable, I explored its radiation principle and analyzed its radiation model. By using cylinder Fourier transform, I obtained the free space radiation fields of leaky coaxial cable with different slots on the outer conductor. After that, this paper analyzed the measure methods and calculating method of the coupling loss detailed, which was the most important electric parameter of leaky coaxial cable, discussed influence factors of coupling loss and the relationship between coupling loss and radiation loss, put forward methods which could be used to improve the theory value of coupling loss. At last the paper analyzed the coupling loss in blind zone, combined with geometrical optics and waveguide matching method deduced the expressions of the coupling loss of leaky coaxial cable, which have vertical and sloping slots on the outer conductor, including rectangular tunnel, circular tunnel and well shielded space indoor, and discussed the external factors that would act on the coupling loss in the tunnel.更多还原