【作者】 王刚；

【导师】 郭筝； 王志忠；

【作者基本信息】 上海交通大学 ， 软件工程， 2007， 硕士

【摘要】 本文主要通过分析射频接收机的相关参数,以噪声系数理论为基础对噪声系数进行再分配,通过把握噪声系数这个关键线索按照待定的增益计划对接收机结构进行优化研究,实现利用噪声系数再分配这种接收机优化设计方法的可行性和实效性。本文的主要目的是要摆脱常规的利用增益来优化接收机结构的方法,从一个全新的角度来分析接收机的性能参数,抓住噪声系数这个与其它参数联系最紧密的关键参数展开分析论证,找出它们之间的相互关系和影响噪声系数的关键因素,从而以此为契机对接收机结构进行优化,然后再通过综合评估接收机的各项性能指标来验证这种优化方法。这样做的好处是设计的思路灵活,趋近设计目标的路径简洁,设计的可靠性容易把握,还可以减少设计工程在系统测试验证过程中出现反复调试电路的几率,使工作量得到压缩节省时间,既能提高工作效率又能降低设计成本。文中作者分三个阶段逐步分析研究论证了这种优化方法。首先,建立本课题的理论模型,通过对接收机噪声理论的分析,结合接收机的各项性能指标,详细阐述了它们之间围绕噪声系数的相互关联,发掘出噪声系数也是能够实时有效地对接收机采取优化措施的一个主导参数和核心因素,随后进一步得出影响噪声系数的关键环节和关键参数。其次,本文以近零中频结构为研究对象,建设性地突破双频接收机的局限性扩展接收机接收频段的兼容性,使得射频前端的设计变得精准简化,然后在此基础上针对设计中难度最大的射频高频段进行优化,建立射频高频信号通过的各个环节的电路模型,从射频输入到中频输出依次仿真,按照设计目标在逐级连接优化中根据每个环节引入优化过程所出现的问题采取相应的解决办法。最后,当整体模型确立以后再次借助ADS仿真工具进行系统仿更多还原

【Abstract】 In this article, an optimum method of RF receiver structure is described that allows the system noise factor take the highest priority to dominate the whole process of this optimum. The general method of such kind optimum is to set noise limit while the receiver gain is playing the dominate issue. But the author gives it up and on the opposite side finds out the theory support from basic noise theory and the components’noise mode, with the relationship between the key parameters of RF receiver and the main factors which impact on the system noise factor. With this baseline, the research and analysis have been launched in steps as below:First of all, a series of noise analysis makes it possible to get basic theory support for the further investigation and optimization. With purpose of finding out who is the key factor in the process of receiver optimum, the relationship and the dependence of each important parameters of receiver have been clarified, therefore, the noise factor takes the king position to guide the optimum direction.Secondly, in order to avoid the receiver band overlap each other it definitely separate and extend the receiver capability from two bands reused as four to four bands working alone within GSM wireless communication system. So that, the front end of all four bands can be designed one by one without any interruption of other receiver bands and also one great achievement of easy application can be found during any customization.Then, it shows the circuit design and optimum of each stage in receiver system following the gain plan and saturation margin budget. With help of ADS simulator tool, the interrelated parameters of each stage, standing for receiver performance, can be obtained in data and更多还原