摘要：本文的研究课题是基于GSM-R系统，研究其需要的滤波器的参数，所设计滤波器中心频率为887MHz（移动台侧）和932MHz（基站侧），带宽为4MHz，插入损耗小于0.25；带内波动为0.5；带外抑制大于65，回波损耗小于20dB。通过引入交叉耦合理论，采用美国公司AWR开发的Microwave Office软件设计了一款同轴腔体带通滤波器。70203

论文首先介绍了论文的研究目的和意义、接着描述了GSM-R技术和滤波器的研究现状以及在无线通信中的重要作用。然后论述了GSM-R系统的结构和干扰来源，之后又介绍了滤波器的基本理论，通过对GSM-R网络运行过程中的干扰现象进行分析，根据干扰的情况及需要达到的网络优化性能，设计一种能够对干扰进行抑制，且具有低插损、高选择性、高带外衰减的滤波器。然后利用滤波器原理对所要设计的GSM-R系统频段带通滤波器参数进行计算。之后利用Microwave Office软件进行滤波器的仿真及优化。根据上述方法设计仿真了一款五阶腔体同轴带通滤波器，该滤波器通过引入两个交叉耦合在通带外低频处产生传输零点，以提高滤波器的带外抑制度。结果表明：利用AWR设计的滤波器的带外抑制、插入损耗、回波损耗等都满足指标要求，同时这款同轴腔体带通滤波器能够实现带外的高抑制性能。

毕业论文关键词：GSM-R系统；干扰；滤波器

Abstract ：The design of this paper is based on the GSM-R system to study the parameters of the filter. The designed filter center frequency is 887MHz (mobile station side) and 932MHz (base station side), the bandwidth is 4MHz, the insertion loss is less than 0.25; The internal fluctuation is 0.5; the out-of-band suppression is greater than 65 and the return loss is less than 20dB. By introducing the cross coupling theory, a coaxial cavity bandpass filter is designed by using Microwave Office software developed by American company AWR.

The paper first introduces the research purpose and significance of the paper, and then describes the research status of GSM-R technology and filter and the important role in microwave communication. Then, the structure and interference sources of the GSM-R system are discussed. The basic theory of the filter is introduced. Based on the analysis of the interference phenomenon in the operation of GSM-R network, according to the interference situation and the network optimization performance, we can design a kind of interference suppression, and have low insertion loss, high selectivity, high band attenuation of the filter. And then use the filter principle to design the GSM-R system band bandpass filter parameters to calculate. And then use Microwave Office software to filter and optimize the filter. According to the above method, a five-cavity coaxial band-pass filter is designed. The filter generates zero transmission at the low frequency of the passband by introducing two cross-coupling to improve the out-of-band suppression of the filter. The results show that the out-of-band rejection, insertion loss and return loss of the filter designed by AWR meet the requirements of the index, and the coaxial cavity band-pass filter can realize the high suppression performance.

KeyWords：GSM-R system；interference；filter

目录

1 绪论 1

1.1论文的研究目的及意义 1

1.2 GSM-R技术及滤波器简介 1

1.2.1 GSM-R 系统和滤波器产生背景及发展 2

1.2.2 GSM-R 系统结构及功能 3

1.2.3 GSM-R 网络结构 4

2 GSM-R系统干扰问题分析