微波光子链路残余相位噪声测量的研究

发布时间：2019-01-27 15:36

【摘要】：微波光子技术是一门新兴的交叉学科,越来越广泛应用于光载无线、射电天文和雷达系统等领域。微波光子链路具有损耗低、带宽大、质量轻、抗电磁干扰以及在信号处理方面的优势。对微波光子链路的性能正在开展各种广泛的研究。本文旨在介绍微波光子链路的构成及工作原理,重点研究微波光子链路和光电探测器的残余相位噪声。论文的主要研究内容如下：(1)综述了微波光子技术的发展以及微波光子链路的应用。介绍了外调制微波光子链路的主要器件和工作原理。(2)研制了激光器的电流驱动与恒温控制电路,并制作了微波光子收发模块,实验测试显示,9小时内激光器输出光功率漂移≤0.4%。(3)解释了相位噪声和随机信号处理的一些概念,介绍了相位噪声测量的基本实验方法。引入了互谱法测量待测器件相位噪声的基本理论,并对该方法进行了理论与仿真研究。(4)高性能雷达系统对微波光子链路的残余相位噪声也有严格要求,微波光子链路引入的附加相位噪声会降低雷达系统的灵敏度。提出了一种测量长距离微波光子链路残余相位噪声的双音互相关方法。该方法可以有效抑制参考源引入测量系统的相位噪声,从而使长距离链路残余相噪的测量成为可能。建立了双音互相关残余相噪测量方法的理论模型并对该测量方法进行了实验研究。基于该方法测量了1m、2km和6km微波光子链路的残余相噪,结果显示6km链路的残余相噪比1m链路恶化了10dB。(5)光电探测器作为微波光子链路的核心器件之一,其残余相噪会恶化整个链路的残余相噪,本文首次将双音信号互相关的方法应用于测量光电探测器的残余相噪。实验研究了反偏电压、输入光功率和非线性对光电探测器残余相噪的影响。结果表明：探测器反偏电压越大,其残余相噪越小；探测器工作在线性区时,增大输入光功率,其残余相噪几乎不变,探测器工作在饱和非线性区时,增大输入光功率,其残余相噪随之增大;探测器非线性越严重,其残余相噪越大。
[Abstract]:Microwave photon technology is a new interdisciplinary subject, which is more and more widely used in optical wireless, radio astronomy and radar systems. Microwave photonic link has the advantages of low loss, large bandwidth, light mass, anti-electromagnetic interference and signal processing. The performance of microwave photonic link is widely studied. In this paper, the structure and working principle of microwave photonic link are introduced, and the residual phase noise of microwave photonic link and photodetector is studied. The main contents of this paper are as follows: (1) the development of microwave photon technology and the application of microwave photonic link are reviewed. The main devices and working principles of the external modulation microwave photonic link are introduced. (2) the current drive and constant temperature control circuit of the laser is developed, and the microwave photonic transceiver module is fabricated. The output power shift of the laser is less than 0.4 in 9 hours. (3) some concepts of phase noise and random signal processing are explained, and the basic experimental methods of phase noise measurement are introduced. The basic theory of cross-spectrum method is introduced to measure the phase noise of the device to be tested, and the theory and simulation of this method are studied. (4) the residual phase noise of microwave photonic link is also strictly required in the high performance radar system. The additional phase noise introduced by microwave photonic link will reduce the sensitivity of radar system. A dual tone cross-correlation method for measuring residual phase noise in long distance microwave photonic links is proposed. This method can effectively suppress the phase noise of the reference source introduced into the measurement system, thus making it possible to measure the residual phase noise in the long distance link. The theoretical model of dual tone cross-correlation residual phase noise measurement method is established and the measurement method is studied experimentally. Based on this method, the residual phase noise of 1mm2 and 6km microwave photonic link is measured. The results show that the residual phase noise ratio of 6km link is deteriorated by 10 dB. (5) as one of the core devices of microwave photonic link, the photodetector is used as one of the core devices of microwave photonic link. The residual phase noise will worsen the residual phase noise of the whole link. In this paper, the method of cross-correlation of two tone signals is applied to measure the residual phase noise of photodetector for the first time. The effects of reverse bias voltage, input optical power and nonlinearity on the residual phase noise of photodetector are experimentally studied. The results show that the larger the reverse bias voltage, the smaller the residual phase noise. When the detector works in the linear region, the residual phase noise of the detector increases when the input optical power is increased, and the residual phase noise increases when the detector works in the saturated nonlinear region. The more nonlinear the detector, the greater the residual phase noise.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN015

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