wcdma光纤直放站射频光收发模块的研究与设计-通信与信息系统专业毕业论文.docx

摘要
第二代移动通信技术已经逐步发展成熟并已经进入商业运营阶段,由于大多数大型网络运营商选择WCDMA技术构建其下一代通信网络,所以, WCDMA是 3G移动通信技术的主流。光纤直放站是基站网路覆盖的重要延伸手段,它具有组网灵活、成本低廉、快速方便等优点。所以,为WCDMA网络覆盖设计的WCDMA 光纤直放站将得到广泛的应用。
WCDMA光纤直放站光收发一体模块是WCDMA光纤直放站系统的核心部件。论文对WCDMA光纤直放站电路设计的理论与电路实现方案进行了详细的分析与论述,并进行了电路设计。文中所设计的光收发模块是具有光电转换、FSK通道、射频补偿、增益自动控制、激光器偏置电流监视、发光功率监测与告警、收光
功率监测与告警、射频功率监测、FSK工作状态监视、FSK调制信号强度控制、
FSK接收信号强度监视等功能的新型光模块。由于WCDMA直放站智能光收发模块的工作频率较高,并因集成了FSK通道与数控电路,电路的设计存在较大的复杂性。
本文首先介绍了直放站的相关原理与技术,作为对直放站光模块应用的介绍;然后,介绍了光模块的电路结构和电路设计方法与技术,这部分主要是关于直放站光收发模块理论的介绍与分析。本文重点进行了光模块主要的电路包括传输线、LD偏置电路与APC电路、低噪声高线性射频电路、FSK调制与解调功能电路与监视控制功能电路的设计。最后,使用测试设备对电路板进行测试分析,电路可以满足设计要求。关键词:光纤直放站,光收发模块,非线性失真,底部噪声,传输线
ABSTRACT
3rd generation(3G)munication technology has made great progress and now,it's begin to be taken into business of panies of the world have made the decision that use WDMA technology to setup
their next works,so WCDMA technology is the leading technology of 3G -optic repeater has many advantages such as easy to setup and convent to do maintenance work, and it can be formed to work
constmctions according to the environment,so the fiber-optic repeater used for
work will be widely used in the future.
The optical transceiver module is the most important part in the WCDMA optical repeater paper discussed the theory of the circuit design and circuit design module designed in the paper has the function that optoelectronic switching,FSK modem,pensation,AGC,LD bias current
monitor,LD optical power monitor and alarm,PD received optical power monitor and alarm,RF power monitor,FSK operating mode monitor,FSK modulation signal power control and FSK received power optical transceiver module for
WCDMA fiber-optic repeater translates the signal at the frequency as high as
2100MHz,and the module also integrated with FSK Modem,monitor and control
circuit,so the circuit design is much plicated.
The paper introduced the technology of fiber-optic repeater which use the optica