【作者】 罗志昕；

【导师】 朱守正；

【作者基本信息】 华东师范大学 ， 无线电物理， 2006， 硕士

【摘要】 近年来，随着气候、能源、政治、军事等多个领域的需求，卫星数据采集系统有着越来越广阔的应用前景。发生在2004年年底的东南亚大海啸使得如何有效地建立起自然灾难的预警系统已成为当前各国关心的一个热门话题；如何对西北等偏远的无人区域的矿产资源进行常年的考察和数据的搜集整理；如何以最小的代价达到最大程度的抑制恐怖主义活动的目的；另外，在军事领域，如何广泛地搜集相关情报也是一个关键的问题。卫星数据采集系统在这些领域都有着不可替代的优势。基于当前这样的背景，本文研究了卫星接收系统中射频电路部分的实现。 本文首先介绍了如何至上而下的从总体上设计卫星接收机，并根据具体的链路预算、干扰情况等等提出总的技术指标，并将该总指标分配到每一个具体电路单元，然后又阐述如何至下而上的利用ADS软件来仿真和验证该指标的可行性和正确性。 文章又从细节上具体的介绍了每个电路单元的设计方法和理论依据，并都给出了相应的实际结果。首先是室外单元(低噪声下变频器)，其包括低噪声放大器，L波段锁相频率合成器和滤波器等，文章第三章重点阐述了L波段低噪声放大器的设计、仿真和实践，选用Agilent PHEMT管子ATF54143作为前级放大，后面级联了两级MMIC，最终设计结果为噪声系数2dB，增益大于45dB。 室内单元则重点介绍如何设计低相噪的锁相频率合成器，首先对于锁相环的原理作了详细的分析，然后选择高性能、低成本、结构简单的方案实现锁相源，本文采用的是AD公司ADF4112和ADF4001分别设计了1.6GHz和140MHz锁相源，并对实际的锁相源模块的相位噪声和频率稳定度进行测量均优于系统性能指标的要求。 详绍分析了DDS的输出频谱以及相位噪声和杂散对DDS频谱特性的影响。选择AD9851作为电路的DDS设计部分，设计并且完成了该电路。经过调试后，测试得到的结果达到了课题的指标要求。 详细阐述了锁相接收机的设计要点，即频率的快速捕获和跟踪，本文选用了一种新型高效的开关鉴相器，其效率比一般的乘法器要高，而且成本低，非常适合在民品中使用。而如何借助辅助扫描电路快速捕获频率是这一电路的难点，调更多还原

【Abstract】 Satellite data collection system has a wider and wider application in clime, energy source, politics, military fields. The tsunami which was happened in South-Asia 2004 had made lots of people lost their life and property. Nowadays, how to establish effective prediction systems is a hot topic in the world. There are a great deal of mine-resources in northwest area of China, which is unmanned. In order to make use of these mine-resources, we should research these areas, collect and analyze data of these areas for a long time first. Anti-terrorism campaign in the world is faced with a new challenge. Nations in the world are researching to build a system as safe as possible at the cost as low as possible. In addition, how to collect information efficiently is an important issue in military area. Satellite data collection system has a unique advantage in these fields. Based on the current background, this paper research and design RF front end module of satellite receiving systems.This paper firstly introduced to the general design of satellite receivers, and then proposed the system technical requirement according specific signal link budget, jamming etc, then allocated it to each specific circuit modules, how to use the ADS software to simulate and certificate the system feasibility and validity has also been discussed.After that, the article describe details of implementation each specific modules and corresponding actual results. Outdoor unit (low noise更多还原