基于电光调制器的高性能RoF链路

发布时间：2018-03-30 22:16

本文选题：光载射频　切入点：动态范围　出处：《西安电子科技大学》2014年硕士论文

【摘要】：光载射频通信(RoF,Radio Over Fiber)将移动通信和光纤通信相结合,实现了两者优势的相融合,相对传统的射频通信系统,其在带宽、损耗、抗电磁干扰等方面具有相当强的优势,在近几年来引起了广泛的研究。然而由于调制器的非线性、光纤的固有色散等特性,使得微波信号在光链路传输之后产生失真,严重降低系统性能,因而研究高性能的RoF链路具有相当重要的意义。本文研究内容总结如下:首先概述了基本的RoF链路模型及其特点,对RoF链路中重要的器件包括激光器、电光调制器(马赫-曾德尔调制器)、光纤、光电探测的基本原理进行分析,并分析了RoF链路中两个主要的指标—无杂散动态范围(SFDR)、周期性衰落。深入研究了一种基于光纤布拉格光栅(FBG)及标准单模光纤(SMF)实现线性优化的方案。实验验证了此方案的线性补偿效果,并深入研究和实验论证了此方案对信号中心频率和带宽的适应性。研究了一个基于双电极马赫-曾德尔调制器(DEMZM)和标准单模光纤(SMF)的高性能传输方案。该结构利用DEMZM的啁啾特性实现抑制周期性衰落,还可以利用光纤的色散对各阶光边带进行不同的移相,加上合适的直流偏置,实现线性优化。本文对此方案做了深入的理论分析,并通过实验验证了通过改变DEMZM的偏置角度可以实现任意光纤在任意频点处的功率衰落,且相对于不进行补偿之前,SFDR同时可以提高14.9d B;实验结果表明三阶抑制最佳工作点的SFDR相对于正交点可提高14.4dB,增益提高4.5dB。最后深入研究和实验论证了此方案对信号中心频率和带宽的适应性,通过实验结果表明当中心频率变化2GHz、带宽增大到1GHz时,IMD3功率相对于补偿前可最小抑制20dB。
[Abstract]:Optical radio frequency communication (RRF) combines mobile communication with optical fiber communication, and realizes the combination of the two advantages. Compared with the traditional RF communication system, it has quite strong advantages in bandwidth, loss, anti-electromagnetic interference and so on. However, because of the nonlinearity of modulator and the inherent dispersion of optical fiber, the microwave signal is distorted after the transmission of optical link, which seriously reduces the performance of the system. Therefore, it is of great significance to study high performance RoF links. The research contents are summarized as follows: firstly, the basic RoF link model and its characteristics are summarized. The important devices in RoF links include lasers. The basic principles of electro-optic modulator (Mach Zehnder modulator, optical fiber, optoelectronic detection) are analyzed. In this paper, two main indexes in RoF link are analyzed, which are no stray dynamic range and periodic fading. A scheme of linear optimization based on fiber Bragg grating (FBG) and standard single mode fiber (SMF) is studied in detail. The linear compensation effect of this scheme, The adaptability of this scheme to the signal center frequency and bandwidth is studied and experimentally demonstrated. A high performance transmission scheme based on the dual-electrode Mach Zehnder modulator and the standard single-mode fiber optic fiber (SMF) is studied. Using the chirp characteristics of DEMZM to suppress periodic fading, It is also possible to realize linear optimization by using the dispersion of optical fiber to phase shift different optical sideband and appropriate DC bias. This paper makes a deep theoretical analysis of this scheme. The experimental results show that the power fading of arbitrary fiber at any frequency can be realized by changing the bias angle of DEMZM. The experimental results show that the SFDR of the third order suppression optimal working point can be increased by 14.4 dB and the gain by 4.5 dB compared with the orthogonal point. Finally, the further research and experiment prove that this scheme can improve the signal. The adaptability of center frequency and bandwidth, The experimental results show that when the center frequency changes 2 GHz and the bandwidth increases to 1GHz, the power of IMD3 can be minimally suppressed by 20 dB compared with that before compensation.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN929.11;TN929.5

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