扩频接收机前端设计技术研究

【作者】 何盛源；

【导师】 陈惠连；

【作者基本信息】 中国工程物理研究院 ， 通信与信息系统， 2007， 硕士

【摘要】 在数字中频接收机中,中频数字处理对中频信号电平的平稳性提出了很高的要求,因此,设计一个性能优越的前端对提高接收机整机性能有着非常重要的作用。本文前端采用超外差式的拓扑结构,主要由低噪声放大器、混频器、滤波器、VGA放大器和锁相频率合成器为主构成的本振频率源等几大模块组成。文中重点利用ADS仿真工具对各模块的主要性能指标开展仿真分析和设计,尤其在自动增益控制(AGC)方案设计中,提出了一种新颖的前向式AGC方案,能较好地解决中频信号电平平稳性问题,并通过仿真验证。在完成仿真设计后,根据仿真结果选取合适的器件来实现了各模块电路。在此基础上,从系统角度对各模块实现的指标进行了综合,给出了样机指标的实测结果及分析,最后总结了本文设计经验和创新点以及工程应用情况,并提出下一步的工作展望。更多还原

【Abstract】 In RF digital receiver, the IF digital processing requires a high stability performance of IF output power. Therefore, a finer RF front-end plays an important role in improving a receiver’s performance.The receiver uses the most used super-heterodyne architecture, consisting of a low noise amplifier, a mixer, two filters, two variable gain amplifier and PLL frequency synthesizer. The ADS tool is used in the article to analyse the specifications of each module. In the AGC plan ,a novel AGC plan is provided to solve the problem about the stability performance of IF output power, and pass through simulation verification. According to simulation results, proper devices are selected to form each module. On the above mentioned basis, the specifications of each module are summarized from the system perspective, and measured results of a propotype is given and analysed. Finally, the experience, innovation andapplication are summarized, and next expectation is proposed.更多还原