VHF频段通信机宽带射频前端系统设计与实现

发布时间：2018-04-30 12:18

本文选题：宽带射频前端 + VHF　；参考：《电子科技大学》2015年硕士论文

【摘要】：当今,无线通信系统朝着低功耗、小型化、多功能方向飞速发展,射频前端作为连接广阔自由空间和基带信号处理之间的桥梁,对其的设计指标要求也越来越高,不仅要求其具有高动态范围及高灵敏度等特点,而且要求其具有更宽的带宽。鉴于此,本论文密切结合项目研究课题,对无线通信系统射频前端电路模块的宽带化处理方案进行了深入的研究,并在此基础上完成VHF频段通信机宽带射频前端系统的研制任务,论文的内容主要包括以下几个方面:1、结合VHF无线信道对射频前端系统参数进行了设计。介绍了VHF无线信道干扰理论,对干扰信号的来源及分类进行了简单的阐述,从理论上分析了其对有用信号的影响,在此基础上简单地介绍了对射频端对干扰信号的抑制措施,最后,对收发信机系统相关参数进行了简单介绍,基于实测信道环境完成VHF频段通信机射频前端系统的参数设计。2、介绍了宽带射频前端主要结构,确定VHF频段宽带通信机射频前端系统设计方案,对系统设计步骤进行了简单介绍,基于成本和小型化要求完成收发系统模块指标的分配和芯片的选型,运用ADS仿真软件分别对收发信机射频前端系统性能进行验证,验证结果基本满足要求。3、介绍了PLL锁相环路工作的基本原理,推导锁相环路中各个模块的相位噪声对其合成信号相噪的影响,在此基础上,基于CG38完成压控振荡器的设计,基于MC145193完成宽带射频前端系统锁相环本振源的设计,测试结果显示,本振源的杂散得到了很好的抑制,相位噪声也满足设计要求,与此同时,在介绍一段短传输线等效模型的基础上完成等功率分配器的方案设计。4、对射频前端放大器的宽带化处理方案进行了论述,在基础上完成低噪声放大器、功率放大器电路的设计,同时对宽带射频前端滤波器(包括带通滤波器与低通滤波器)、基带I/Q匹配电路、基带I/Q偏置电路、零中频抗直流偏移、DC-DC变换电源及调制解调器等模块电路进行了方案的设计与调试,完成整个VHF频段宽带通信机射频前端系统的设计与调试,测试结果显示,所有指标都基本达到了系统设计要求。
[Abstract]:Nowadays, wireless communication system is developing rapidly in the direction of low power consumption, miniaturization and multifunction. As a bridge between wide free space and baseband signal processing, RF front-end is required more and more. It is required not only to have high dynamic range and high sensitivity, but also to have wider bandwidth. In view of this, this paper closely combines the project research topic, carries on the thorough research to the wireless communication system RF front-end circuit module wideband processing scheme. On this basis, the research task of broadband RF front-end system of VHF band communication machine is completed. The main contents of this paper include the following aspects: 1. The parameters of RF front-end system are designed based on VHF wireless channel. In this paper, the theory of VHF radio channel interference is introduced, and the source and classification of interference signal are briefly described. The influence of interference signal on useful signal is analyzed theoretically. On the basis of this, the measures of suppressing interference signal at RF terminal are briefly introduced. Finally, the related parameters of transceiver system are briefly introduced. The design of RF front-end system of VHF frequency band communication machine is completed based on the measured channel environment. The main structure of broadband RF front-end is introduced. The design scheme of RF front-end system of VHF broadband communication machine is determined. The design steps of the system are simply introduced. Based on the cost and miniaturization requirements, the allocation of the module index and the selection of the chip are completed. The performance of RF front-end system of transceiver is verified by using ADS simulation software, and the verification results basically meet the requirement of .3.The basic principle of PLL phase-locked loop is introduced. The effect of the phase noise of each module in the PLL on the phase noise of the synthesized signal is deduced. On this basis, the design of the VCO based on CG38 and the design of the local oscillator of the phase-locked loop (PLL) of the wide-band RF front-end system based on MC145193 are completed. The test results show that the stray of the local oscillator is well suppressed, and the phase noise can meet the design requirements, at the same time, On the basis of introducing the equivalent model of a short transmission line, the scheme design of equal power divider is completed. The broadband processing scheme of RF front-end amplifier is discussed. On the basis of this, the low noise amplifier and power amplifier circuit are designed. At the same time, wideband RF front-end filters (including band-pass filters and low-pass filters, baseband I / Q matching circuits, baseband I / Q bias circuits, The design and debugging of the zero-intermediate frequency anti-DC offset DC-DC converter power supply and modem are carried out. The design and debugging of the RF front-end system of the whole VHF broadband communication machine are completed. The test results show that, All the indexes basically meet the system design requirements.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN92

【参考文献】