【作者】 王骞；

【导师】 席晓莉；

【作者基本信息】 西安理工大学 ， 通信与信息系统， 2008， 硕士

【摘要】 随着卫星导航技术的快速发展,越来越多的国家发展了自己的导航系统。由于各种导航系统的卫星在空间的分布有限,提供卫星定位服务的精确度、安全性、可靠性和可用性无法得到保障,因此对应用多种卫星导航系统组成的多模导航接收系统的研究,近年受到广泛重视。天线是卫星导航系统中非常重要的一部分,在一定程度上决定着卫星导航系统的性能。具有多频段、圆极化和宽带特点的多模导航接收天线是近年卫星接收天线研究的热点。本文针对多模卫星导航接收天线的需求,设计了几种可工作在卫星导航频段的单频、双频及三频段天线,并采用数值仿真方法对天线结构进行了优化。具体内容如下:本文首先介绍了常用的卫星导航接收天线,即四臂螺旋天线和微带天线的理论分析方法。其次依据微带天线的相关理论,设计了单频段圆极化微带天线、多层贴片结构的双频段及三频段的圆极化微带天线,其中单频天线的圆极化分别采用单馈电及双馈电的方法实现,而多频天线的圆极化主要采用单馈电实现。为了使天线小型化,同时便于加工,本设计中去掉了传统的在多层贴片之间引入空气层的结构。再次本文依据四臂螺旋天线的辐射机理及馈电特点,设计了单频段四臂螺旋天线及封闭式和多臂式的双频段四臂螺旋天线的基本结构,并且同时设计了单频段和双频段四臂螺旋天线的匹配网络。本文采用基于有限元法的ANSOFT HFSS软件对天线性能进行了数值仿真,并对天线结构进行优化。设计出了能够分别工作在1.27GHz和1.575GHz以及同时工作在以上两个频段的微带天线和四臂螺旋天线。本文设计的三频段圆极化微带天线能够同时工作在1.27GHz、1.575GHz和2.5GHz。这些天线均能够满足卫星导航系统的要求。更多还原

【Abstract】 With the development of satellite navigation, many countries have had their own satellite navigation. Because of the limitation of the independence system satellite constellation, service precision, reliability, security and availability provided by the system can not be guaranteed, the research of the multi-mode satellite navigation system is attached importance to. Antenna is a very important unit of the satellite navigation system. The performance of the receiver is affected by it partly. The antenna with the character of circularly polarized, working at multi-frequency and wide band is paid attention to for the multi-mode satellite navigation system. In this paper, the single frequency antennas, dual-frequency antennas and multi-frequency antenna are designed for the multi-mode working at multi-frequency. These antennas are simulated and optimized by applying the numerical method of electromagnetic field. The details of this paper can be introduced as follows:Quadrifilar helix antenna (QHA) and microstrip antenna are widely used in satellite navigation system. The academic methods of these antennas are introduced firstly. Secondly, the single frequency, dual-frequency and multi-frequency circularly polarized (CP) microstrip antennas are designed according to the theory. In order to make the single frequency microstrip antennas have the character of CP, the methods of single feed and dual feeds are applied. And the multi-frequency CP microstrip antennas are fed by dual signals. The air-gap layer between two patches is get rid of in order to make the antenna compact and easy to fabricate. Lastly, the single frequency QHA, the dual frequency closed QHA and multi-arm QHA are designed according to the theory. Simultaneously, the feeding networks of the single frequency and dual frequency QHAs are designed, too. These antennas are simulated and optimized by the software of ANSOFT HFSS that is based on the Finite Element Method (FEM). The single frequency CP microstrip antennas and QHAs working at 1.27GHz and 1.575GHz respectively are designed. And the dual frequency CP microstrip antennas and QHAs working at above- mentioned frequency are designed, too. In this paper, the triple-frequency CP microstrip antenna works at 1.27GHz, 1.575GHz and 2.5GHz. These antennas could be used in the satellite navigation system.更多还原