【作者】 段瑞敏；

【导师】 林金桐；

【作者基本信息】 北京邮电大学 ， 通信与信息系统， 2013， 硕士

【摘要】 模拟光链路是微波光子学的重要组成部分,融合了微波技术和光子技术。利用光子技术的优势,如消除电磁干扰,高隔离度,低损耗等,实现了微波信号的光域传输和处理。本论文对模拟光链路的性能进行了详细的理论和仿真分析,提出了基于数字信号处理(DSP)的三阶交调失真抑制技术,提出了基于双并行马赫增德尔强度调制器(DPMZM)的全光下变频方案,并结合数字后补偿技术,实现了高频信号的失真抑制。论文主要工作有：1.模拟光链路性能的理论与仿真分析论文重点介绍了使用MZM的强度调制直接探测链路的性能评价指标,包括链路增益、噪声指数和动态范围等。给出了指标的具体定义,理论推导和仿真分析了各指标和激光器输出光功率、调制器半波电压以及调制器偏置角度等链路参数的关系。参考仿真结果,对链路性能的影响因素有了更加形象的认识,得到了链路性能的优化方法。2.基于数字信号处理的三阶交调失真抑制技术提出了基于DSP的三阶交调失真抑制技术,给出了理论分析与实验验证。测量了MZM强度调制器的传输性能,一阶输出信号和三阶失真分量与输入射频功率的关系。使用DSP后补偿技术抑制了三阶交调失真分量,由实验结果可知,失真被抑制了20dB左右,但是该方案的性能受限于信号的频率,随着频率的增加,性能将会恶化。3.基于双并行强度调制器的全光下变频方案提出了基于DPMZM的频率下变换方案,并结合数字后补偿技术,实现了三阶交调失真分量的抑制。频率变换性能可以通过改变调制器的偏置电压、本振信号功率以及激光器的输出功率灵活地调节。理论分析和实验验证了这些因素对变频效率的影响。同时,还验证了矢量信号在全光下变频链路中的传输,分析了传输性能和载波频率以及本振信号功率的关系。更多还原

【Abstract】 Analog Photonic Link (APL) is the essential part of Microwave Photonics, converging microwave and photonics technologies. The transmission and processing of microwave signal in optical domain are realized, taking advantages of photonics, such as immunity to electromagnetic interference, high isolation, and low loss.In this thesis, the performance of APL has been researched through theoretical derivation and, simulation analysis. A nonlinear distortion compensation scheme for the intensity-modulated APL based on post digital signal processing has been proposed and experimentally demonstrated, In addition, a photonic microwave frequency down-conversion approach based on integrated Dual Parallel Mach-Zehnder Modulator (DPMZM) has been proposed. Incorporating digital post compensation technique, third-order intermodulation distortion (IMD3) has been suppressed successfully for high frequency signal. The works in this dissertation include:1. Theoretical derivation and simulation analysis of APLs’ performanceIn this thesis, a set of parameters have been introduced to describe the performance of intensity-modulation direct-detection (IMDD) APL with Mach-Zehnder Modulator (MZM), including gain, noise figure and dynamic range. The detailed definitions of these parameters are introduced, as well as the relationships among these parameters and their main effecting factors, such as input optical power to the modulator, modulator half-wave voltage and modulator bias angle. According to the simulation results, several approaches to optimize the performance of APL have been identified.2. IMD3suppression technology based on digital signal processingAn IMD3suppression scheme for the intensity-modulated APL based on digital signal processing has been proposed, as well as theoretically analyzed and experimentally demonstrated. The transfer characteristics of intensity modulator used in our experiment has been measured. The functions of the output fundamental signal power and IMD3power with input signal power have been also obtained. Using this scheme, IMD3components have been suppressed about20dB. However, this scheme is frequency limited, performance deteriorating with signal frequency increasing.3. Photonic microwave frequency down-conversion approach based on integrated Dual Parallel Mach-Zehnder ModulatorA photonic microwave frequency down-conversion approach based on integrated DPMZM has been proposed. Incorporating digital post compensation technique, IMD3has been suppressed successfully for high frequency signal. The conversion performance can be tuned flexibly by simply adjusting bias voltages of the modulator, local oscillator (LO) power and optical power. The influence of these parameters on the conversion efficiency have been theoretically analyzed and experimentally verified. At the same time, the transmission of vector signal in this photonic frequency downconversion links has been experimentally demonstrated. The dependence of transmission performance on carrier frequency and LO power has also been analyzed experimentally.更多还原