受限空间适应型圆极化天线研究
发布时间：2018-09-08 16:42
【摘要】：受限空间环境中的电波覆盖特性关系到受限空间中无线通信的可靠性,会直接影响其中载体运行及人员的安全。由于圆极化波具有抗多径衰落、抗极化失配等特点,因而被认为能够提供比较均匀的电波覆盖,并且已经有工程实例将圆极化天线作为受限空间中的发射天线使用,如西班牙马德里隧道。然而圆极化波在受限空间的覆盖情况到底如何,并没有明确的结论,因为受限空间边界复杂,反射波的极化多变,目前有关受限空间中圆极化波传播的研究成果还很少,因此有必要对受限空间中圆极化天线及其产生的电波覆盖进行深入的研究。本文利用基于镜像原理的射线追踪法,对圆极化波在矩形硬边界受限空间中的电波覆盖特性进行研究,并据此提出了两种类型的圆极化阵列天线。这两种天线分别使用蝴蝶结型天线和交叉振子天线作为阵列单元,横截面积小,可在风阻较大的受限空间中使用。本文的主要贡献有如下几个方面:1.研究了基于镜像原理的射线追踪方法,并且将电波覆盖的研究与天线具体特性相结合。研究了矩形硬受限空间中不同极化波的传播规律,对比分析了不同极化波的传播特性差别,发现圆极化波在矩形隧道中的覆盖特性处于水平极化和垂直极化两种情况之间,分析了圆极化波这一特性的成因。2.分析了单向端射和双向端射的发射天线在受限空间中的电波覆盖特性。根据能量均匀性和系统能效因子,研究了在长受限空间中通过改变天线纵向分布位置来实现电波覆盖特性优化的方法,对受限空间中天线分布的实际设计有指导意义。3.采用正交放置的蝴蝶结型天线为单元,设计了低风阻圆极化阵列天线。此阵列天线工作在900 MHz,在两端辐射旋向相同的圆极化波,可作为发射圆极化波的多天线系统的单元使用,具有结构紧凑、安装方便的优点。4.采用交叉振子单元设计、并制作了单向辐射和双向端射的交叉振子单元圆极化阵列天线,两个阵列天线都工作在当前铁路通信系统正推广使用的1.7 GHz频段,可分别用于发射圆极化波的单天线或多天线系统。
[Abstract]:The radio coverage in restricted space environment is related to the reliability of wireless communication in restricted space, which will directly affect the carrier operation and the safety of personnel. Because circular polarization wave has the characteristics of anti-multipath fading and anti-polarization mismatch, it is considered to be able to provide uniform radio coverage, and has been used as a transmitting antenna in confined space by engineering examples. For example, Madrid Tunnel, Spain. However, there is no clear conclusion on the coverage of circular polarized waves in confined space. Because the boundary of restricted space is complex and the polarization of reflected waves is changeable, there are few researches on the propagation of circular polarized waves in confined space. Therefore, it is necessary to study circularly polarized antennas and their radio coverage in confined space. In this paper, the radio wave coverage characteristics of circularly polarized waves in rectangular hard boundary confined space are studied by means of ray tracing method based on mirror image principle, and two types of circularly polarized array antennas are proposed. The two kinds of antennas use bow antenna and cross dipole antenna as array elements respectively. The cross section area of these two antennas is small and can be used in the limited space with high wind resistance. The main contributions of this paper are as follows: 1. The ray-tracing method based on mirror image principle is studied, and the research of radio coverage is combined with the characteristics of antenna. The propagation law of different polarization waves in rectangular hard confined space is studied. The difference of propagation characteristics of different polarization waves is compared and analyzed. It is found that the coverage characteristics of circular polarization waves in rectangular tunnels are between horizontal and vertical polarization. The cause of formation of circular polarization wave is analyzed. The radio coverage characteristics of one-way and bidirectional end-emitting antennas in confined space are analyzed. According to the energy uniformity and system energy efficiency factor, the method of optimizing the radio coverage characteristics by changing the position of antenna longitudinal distribution in long confined space is studied, which is of guiding significance to the practical design of antenna distribution in restricted space. A circular polarization array antenna with low wind resistance is designed by using an orthogonal bow-tie antenna as a unit. The array antenna works at 900 MHz, and radiates the same circular polarization wave at both ends. It can be used as a unit of multi-antenna system that emits circular polarization wave. It has the advantages of compact structure and convenient installation. A circular polarization array antenna with unidirectional radiation and bidirectional end emission is designed and fabricated by using cross oscillator element. Both array antennas are working in the 1.7 GHz frequency band which is being popularized in railway communication system. Single antenna or multi-antenna system can be used to transmit circular polarization wave respectively.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN821.1
本文编号：2231091
[Abstract]:The radio coverage in restricted space environment is related to the reliability of wireless communication in restricted space, which will directly affect the carrier operation and the safety of personnel. Because circular polarization wave has the characteristics of anti-multipath fading and anti-polarization mismatch, it is considered to be able to provide uniform radio coverage, and has been used as a transmitting antenna in confined space by engineering examples. For example, Madrid Tunnel, Spain. However, there is no clear conclusion on the coverage of circular polarized waves in confined space. Because the boundary of restricted space is complex and the polarization of reflected waves is changeable, there are few researches on the propagation of circular polarized waves in confined space. Therefore, it is necessary to study circularly polarized antennas and their radio coverage in confined space. In this paper, the radio wave coverage characteristics of circularly polarized waves in rectangular hard boundary confined space are studied by means of ray tracing method based on mirror image principle, and two types of circularly polarized array antennas are proposed. The two kinds of antennas use bow antenna and cross dipole antenna as array elements respectively. The cross section area of these two antennas is small and can be used in the limited space with high wind resistance. The main contributions of this paper are as follows: 1. The ray-tracing method based on mirror image principle is studied, and the research of radio coverage is combined with the characteristics of antenna. The propagation law of different polarization waves in rectangular hard confined space is studied. The difference of propagation characteristics of different polarization waves is compared and analyzed. It is found that the coverage characteristics of circular polarization waves in rectangular tunnels are between horizontal and vertical polarization. The cause of formation of circular polarization wave is analyzed. The radio coverage characteristics of one-way and bidirectional end-emitting antennas in confined space are analyzed. According to the energy uniformity and system energy efficiency factor, the method of optimizing the radio coverage characteristics by changing the position of antenna longitudinal distribution in long confined space is studied, which is of guiding significance to the practical design of antenna distribution in restricted space. A circular polarization array antenna with low wind resistance is designed by using an orthogonal bow-tie antenna as a unit. The array antenna works at 900 MHz, and radiates the same circular polarization wave at both ends. It can be used as a unit of multi-antenna system that emits circular polarization wave. It has the advantages of compact structure and convenient installation. A circular polarization array antenna with unidirectional radiation and bidirectional end emission is designed and fabricated by using cross oscillator element. Both array antennas are working in the 1.7 GHz frequency band which is being popularized in railway communication system. Single antenna or multi-antenna system can be used to transmit circular polarization wave respectively.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN821.1
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