基于微波光子技术的综合射频系统及其应用研究

发布时间：2018-02-27 23:16

本文关键词： 综合射频系统微波光子多频率变换偏振不敏感卫星转发　出处：《北京邮电大学》2014年博士论文　论文类型：学位论文

【摘要】：综合射频系统通过一套共用的软、硬件结构可实现多种射频功能,具有统一频谱管控、灵活资源调配、减小设备冗余、降低维护成本等一系列优点,在国防电子、卫星载荷和通信网络方面具有广泛的应用前景。但目前面临处理带宽、传输损耗和电磁干扰等方面的问题。新兴的微波光子技术具有宽带、低损耗、高射频隔离度和强并行处理能力等优势,论文创新性的将微波光子技术应用于综合射频系统,取得的主要创新成果如下：针对综合射频系统面临的宽带、多频本振产生和分布问题,论文提出了一种基于双光频梳的光生多本振产生方法,该方法可以利用3个固定频率的射频本振产生一系列不同频段、且相互分离的射频本振,产生的本振数目可随光频梳谱线数的增加而增加。由于光生多本振系统与光纤兼容,可支持大面积射频本振的分布和共享。本文利用该方法成功实现了L-Ka频段内幅度均匀的多射频本振产生。针对综合射频系统面临的宽带、多频率变频问题,本文提出了两种基于光频梳的灵活变频方法。第一种方法通过将光频梳和调制到光上的多频段信号差拍,可以实现多频段射频信号的不同频段同时下变频到不同的中频,且支持频谱反转、交换等灵活的频谱操控功能。实验演示了将双频段射频信号同时下变频到不同的中频,相比背靠背传输,信号EVM恶化7.5%。另一种方法是将输入射频用光频梳多路复制并与另一光频梳差拍,然后使用信道化滤波分离出各差拍信号,从而实现单一射频信号同时到多个频段的变频与广播。实验实现了6.1GHz信号同时下、上变频到3.9GHz、4.1GHz、11.9GHz、19.9GHz和27.9GHz。各信道最大串扰为-13.6dB,相比背靠背传输,信号EVM恶化9.3%。针对分布式光纤链路所面临的偏振态抖动影响,论文研究了一种适合多路共用的基于正弦波的扰偏方法。理论分析结果表明,当扰偏深度达到一个特定值时,光载波的直流分量与偏振抖动无关。基于上述分析,实验实现了对外界偏振抖动信号大于40dB的抑制,并且在远端电光调制和远端光子变频应用中,利用该方法分别实现了将信号的偏振相关功率抖动控制在0.6dB和0.9dB以内。最后,论文开展了基于微波光子技术的综合射频系统在可重构分布式天线系统与通信卫星转发器方面的应用研究。1)论文利用光子射频交换和光纤射频传输设计了一种射频可重构的光纤分布式天线系统,并成功研制相关原理样机,实现了多信号的频率重构、路由重构以及大容量射频资源的灵活调配；2)与中国科学院和中国空间技术研究院合作,利用光子射频交换和宽带多频率光子变频技术,设计并实现了一套新型的通信卫星转发器系统,可支持C(6/4GHz)、Ku(14/12GHz)和Ka(30/20GHz)三个频段中任意上行频率到下行频率的转发。
[Abstract]:The integrated radio frequency system can realize a variety of RF functions through a set of common software and hardware structure. It has a series of advantages such as unified spectrum control, flexible resource allocation, reducing equipment redundancy, reducing maintenance cost and so on. Satellite payload and communication network have a wide application prospect. However, it is faced with the problems of processing bandwidth, transmission loss and electromagnetic interference, etc. The emerging microwave photonic technology has broadband, low loss, and so on. With the advantages of high RF isolation and strong parallel processing ability, this paper innovatively applies the microwave photonic technology to the integrated RF system. The main innovative achievements are as follows:. Aiming at the generation and distribution of wideband and multi-frequency local oscillator in integrated radio frequency system, a method based on double optical comb is proposed in this paper. This method can use three fixed frequency RF local oscillator to produce a series of different frequency bands and separate RF local oscillator from each other. The number of local oscillator can increase with the increase of optical frequency comb lines, because the photogenerated multi-local oscillator system is compatible with optical fiber. It can support the distribution and sharing of large area RF local oscillator. This method has been successfully used to generate multi-RF local oscillator with uniform amplitude in L-Ka band. Aiming at the problem of broadband and multi-frequency conversion in integrated RF system, two flexible frequency conversion methods based on optical comb are proposed in this paper. Different frequency bands of multi-band radio frequency signals can be converted to different intermediate frequencies at the same time, and the flexible spectrum manipulation functions such as spectrum inversion and switching can be supported. The experiment demonstrates the simultaneous downconversion of dual-band radio frequency signals to different intermediate frequencies. Compared with back-to-back transmission, the signal EVM worsens 7.5%. Another method is to multiplex the input RF with optical comb and then separate the beat signal by channelization filter. Thus, a single radio frequency signal can be converted and broadcast simultaneously to multiple frequency bands. Experimental results show that the single radio frequency signal can be downconverted simultaneously to 3.9 GHz, up to 4.9 GHz, and 27.9GHz. The maximum crosstalk of each channel is -13.6dB. compared with back-to-back transmission, the signal EVM deteriorates by 9.3GHz. The maximum crosstalk of each channel is -13.6dB.Compared with back-to-back transmission, the signal EVM is worse than 9.3GHz. Aiming at the effect of polarization state jitter on distributed fiber links, a sinusoidal perturbation method suitable for multiplexing is studied in this paper. The theoretical analysis results show that when the depth of disturbance reaches a specific value, The DC component of the optical carrier is independent of the polarization jitter. Based on the above analysis, the suppression of the external polarization jitter signal greater than 40 dB has been realized experimentally, and it has been used in the remote electro-optic modulation and remote photon frequency conversion applications. Using this method, the polarization dependent power jitter of the signal is controlled within 0.6dB and 0.9dB, respectively. Finally, In this paper, the application of integrated radio frequency system based on microwave photonic technology in reconfigurable distributed antenna system and communication satellite transponder is studied. Frequency-Reconfigurable Fiber distributed Antenna system, A prototype of related principles has been successfully developed to realize multi-signal frequency reconfiguration, routing reconfiguration and flexible allocation of large capacity RF resources) in cooperation with the Chinese Academy of Sciences and the China Academy of Space Technology. A new communication satellite transponder system is designed and implemented using photonic radio frequency switching and broadband multi-frequency photon conversion technology. It can support the forwarding of any uplink frequency to downlink frequency in three frequency bands, namely, 6 / 4 GHz Kuan (14 / 12 GHz) and Kaen 30 / 20 GHz).
【学位授予单位】：北京邮电大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TN929.1

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