目前基于微波技术的射频通道带宽与频率受限、多频率变频能力受限、通用性差,严重制约了高通量卫星的频谱覆盖范围和大带宽多路变频能力.针对这一问题,本文在对微波光子射频通道研究现状对比分析的基础上,提出基于并联型架构的宽带跨频段微波光子射频通道实现方法,开展了相应的仿真分析及实验验证.测试结果表明:该射频通道下变频输入频率可覆盖27 GHz～52 GHz,输出频率可覆盖17 GHz～24 GHz;上变频输入频率可覆盖25 GHz～27 GHz,输出频率可覆盖37 GHz～43 GHz,且该射频通道工作带宽优于2 GHz,带内平坦度优于3 dB,变频增益优于?10 dB,无杂散动态范围优于100 dB?Hz2/3.

面向超宽带、高灵敏度、复杂电磁环境下的多信号接收处理需求,提出了基于光电混合的超宽带一体化接收处理方案.与传统的微波接收方法相比,采用微波光子信道化统一中频变频接收通道,发挥光子技术在并行、复用、小型化集成等方面的优势,在光域上完成对超宽带微波信号信道化滤波和下变频处理,节省了众多微波器件和电缆,减轻了系统重量、体积和功耗,增加了信号截获概率,实现在大带宽内同时处理多个窄带和宽带信号的能力,增强了系统可靠性,提升了系统效率.采用数据缓存加多级数字信道化处理方案,缓解高速采集数据与实际信号处理芯片在数据吞吐量、运行速度等的不匹配,能够满足大小带宽信号的输入,克服了单级信道化同时处理宽窄信号的性能不足.该文提出的方案,尤其适用于侦干探通多功能一体化载荷和6G卫星通信系统对于超宽带电磁信号的统一接收处理.

随着卫星通信技术的飞速发展,以及卫星多功能融合技术的需求,未来卫星通信正朝着多频段、大带宽、多波束、配置灵活的方向发展,这对传统基于电子技术的卫星载荷多格式多频段信号接收及中继转发提出了挑战.本文利用微波光子技术格式透明、工作频段透明的优势,给出了基于微波光子技术的宽带通信卫星载荷结构,该结构在采用传统微波高功率发射及多路信号合成基础上,引入微波光子技术进行多格式多频段微波信号的光调制、光域微波信号宽带接收及转发.在此基础上建立了相应的用于宽带通信卫星的微波光子链路测试验证系统,对诸如噪声系数、系统线性特性及宽带信号传输特性等主要性能进行了详尽的分析与验证,测试结果表明该系统在S/C/Ku/ka频段具有良好的宽带线性特性和传输性能,且该性能与系统的调制灵敏度和解调灵敏度密切相关.

高通量卫星(High Throughput Satellite,HTS)是新一代宽带通信卫星的统称.一方面可用于远程教育、远程医疗、应急救灾等公益事业,另一方面可以为个人和企业提供宽带多媒体和高速率的Internet等商业应用.首先介绍了高通量卫星通信的概念,对基于微波光子技术的高通量卫星进行需求分析,接着对国内外高通量卫星的发展现状进行了详细介绍并进行了对比分析.在此基础上,给出了基于微波光子技术的高通量卫星通信系统组成初步构想,最后给出了总结和展望.基于微波光子技术高通量卫星可实现星载宽带信号光域窄带处理、大规模交换转发和光控波束形成,不仅能够解决当前高通量卫星应用中的问题,满足多用户多业务需求,还兼具频谱效率高、宽带大、吞吐量高等优点,有助于推动卫星载荷向宽带化、阵列化、一体化、小型化和通用化发展,具有重要的意义.

随着卫星通信大容量、跨频段、多业务需求的不断增加,卫星载荷正朝着多频段一体化综合接收处理方向发展.为满足卫星载荷大容量、多信号处理功能,需要同时提供多个载频信号作为参考.采用微波光子技术可根据用户需求生成光频梳作为多载频信号,满足多频段一体化综合接收处理对多本振源的需求.文章首先从现有多载频信号生成方法的局限性出发,确定高质量光载波抑制单边带信号(SSB-OCS)结合循环频移的多载频信号生成方法.接着提出基于并联马赫-曾德尔调制器(MZM)的光载波抑制单边带信号生成方法,使得其中两个MZM工作在单边带调制方式,另一个MZM工作在偶数阶抑制方式,结合90度和180度光移,产生具有高边带抑制比的光载波抑制单边带信号.最后在此基础上给出基于并联MZM循环频移的多载频信号生成方法,仿真结果表明所生成的多载频信号载波数目为60以上、边带抑制比为30dB、最大功率起伏为4.4dB,且其中有20个载波的功率起伏在1dB以内.该方法可有效生成高平坦高边带抑制比多载频信号,为卫星载荷的多频段一体化综合接收处理提供相应技术支撑.

文章以光子集成技术在未来卫星宽带通信与中继一体化系统应用为出发点,开展光子集成载荷应用需求分析,完成了模拟光处理与数字光处理、模拟片上处理与离散光处理的区别分析及特性梳理.重点介绍了现行的光子载荷搭载验证情况,完成光子载荷与传统射频载荷体积、重量、功耗对比分析.在此基础上,提出一种全芯片架构的光子处理转发载荷系统,并完成相应的功能拆解及业务划分,梳理下一步需要重点攻关的片上关键技术,为构建通用化、小型化、多波束并行的高通量卫星通信载荷系统提供技术支撑.

随着对高精度探测的不断追求,未来雷达系统正朝着大带宽的方向发展.目前的雷达系统,主要利用传统的微波技术生成雷达信号,受到电子瓶颈限制,单路带宽仅在2 GHz左右,难以满足高精度雷达探测的技术需求.微波光子信号生成技术具有大带宽的技术优势,被认为是可突破电子瓶颈的一种有效技术手段.可将微波光子信号生成技术引入雷达系统中,直接生成带宽高达41 GHz的雷达信号,从而大幅提高雷达系统的探测分辨率.文章首先介绍了微波光子大带宽脉冲压缩信号生成技术的应用情况,然后分类介绍了微波光子大带宽脉冲压缩信号生成技术的工作原理、主要实现方法及研究进展,最后对各类微波光子大带宽脉冲压缩信号生成技术进行了对比分析,并分析了限制其实际应用的具体问题.

随着卫星通信技术的飞速发展,以及卫星多功能融合技术的需求,未来卫星通信正朝着多频段、大带宽、多波束、配置灵活的方向发展.目前广泛应用于各个领域的卫星通信射频前端,主要采用传统的微波技术进行微波信号的信道化接收变频,带宽限制在GHz以下,无法满足大瞬时带宽信道化接收变频需求.将微波光子技术引入卫星通信射频前端可有效突破电域信道化接收变频技术瓶颈,简化射频前端的系统架构,提高卫星载荷性能.本文首先介绍了星载微波光子信道化接收变频技术的特点及基本结构.接着分类介绍了微波光子信道化接收变频的工作原理、主要实现方法及研究进展,最后给出大瞬时带宽微波光子信道化变频技术发展趋势及应用前景,为大瞬时带宽微波光子信道化接收变频设计及应用提供技术支撑.

文章针对微波域滤波器只能对提前设计好的特定频段、特定带宽使用的局限性而提出微波光子滤波器,其中,基于受激布里渊散射效应(SBS)的微波光子滤波器不仅拥有可调谐、可重构特性,而且由于其阈值低、调谐范围大和系统稳定性较好等优点而引起广泛关注.文章对比总结了从2011年以来国内外学者在该滤波器方面取得的重大研究成果并得出其未来的发展趋势.选取性能更优越的光频率梳技术进行SBS增益谱叠加,进而利用滤波器频谱带宽可重构的方法来实现基于SBS的滤波器设计.通过optisystem和matlab软件进行仿真分析,得到了3dB带宽为137MHz、形状因子为0.75、可调谐范围为0～20GHz的基于SBS的微波光子滤波器.从滤波器性能得出其可应用于包括卫星通信系统在内的各系统中的收发机,将大频率带宽范围的GHz宽带信号划分为并行的百MHz窄带信号,以便于用低频器件进行相关处理.

In this paper ,we researched the main parameters of microwave photonic transmit link in the near space ,in-cluding influence factors of the performance .Then we set up a near space microwave photonic transmit link model with vari-ous optical power ,DC bias and RF frequency .We presented the simulated results of near space microwave photonic transmit link such as link RF gain, noise figure,and so on.All these results can provide fundamental basis for near space microwave photonic transmit link .

In this paper, the technical characteristics and the application background of microwave photonics frequency conversion were introduced. Several typical schemes were compared,the principle of frequency conversion based on series of LiNbO3 modulators was analyzed in detail, a new LN-MZ frequency conversion scheme was put forward, serials of system simulation was made. Essential theoretical basis and technical support were provided for new scheme of microwave photonics frequency conversion of satellite payloads.

In this paper,the developing requirement and characteristics of satellite data bus are analyzed. The develop-ment,application and prospect of data bus such as MIL-STD-1553B and FC-AE are introduced. Based on the data bus FC-AE,a new optical data bus FC-SE for satellite which is compatible with MIL-STD-1553B is introduced. And the architecture, protocol characteristics,and service are studied. The data bus FC-SE can process high data with optical wide band, and also process low data with MIL-STD-1553B. The FC-SE data bus satisfies multi-data and multi-service requirements of the satel-lite data bus.

The technology characteristic and application background of Microwave Photonics Frequency Conversion are introduced. On the basis of external modulation and microwave frequency conversion, microwave frequency conversion meth-od based on serial MZM modulation is described. The microwave frequency conversion simulation model and simulation a-nalysis based on serial MZM modulation is also studied. All the results are essential theoretical bases and technical support for the microwave frequency conversion simulation scheme based on serial MZM modulator.

An optoelectronic oscillator ( OEO) method for Satellite Payloads is analyzed,which is used to meet the de-mands of aerospace for high frequency and low phase noise signal. Firstly, the application background and technology char-acteristic of the OEO are introduced. Secondly,the principle,the oscillator threshold, the frequency and the amplitude of the OEO are discussed with mathematical method. Finally, the phase noise performance of the OEO is analyzed in detail. The result shows that the OEO can generate microwave signal with high performance( -163dBc/Hz @10KHz), and the phase noise of the microwave signal is independent of the oscillator frequency. The OEO can meet the demands of microwave signal generating for satellite payloads.

考虑到星间微波光子链路传输损耗大且多路微波信号之间交调干扰严重,利用前置光放大来提高链路的信号噪声失真比RSNDR.建立了两路输入前置光放大星间微波光子链路模型,推导出了RSNDR的解析表达式.通过优化马赫-曾德尔调制器的直流偏置相移,使得在给定输入射频信号功率条件下RSNDR最大,并进一步分析了前置光放大器参数对最优直流偏置相移和RSNDR的影响.仿真结果表明,前置光放大改变了影响RSNDR的主要因素,使信号放大的倍数大于噪声和三阶交调(IM3)放大的倍数,从而提高了链路的RSNDR.当前置光放大器增益为20 dB、噪声系数为3 dB时,最优的RSNDR比不加前置光放大器时提高24 dB.前置光放大器增益和噪声系数对最优的RSNDR影响很大,而对最优的直流偏置相移几乎无影响.

An optical preamplifier is utilized to improve the signal-to-noise and distortion ratio (SNDR) of intersatellite microwave photonic links employing a Mach-Zehnder modulator under dual-tone modulation. The resulting SNDR at an appropriate direct current (DC) bias phase shift is additionally investigated without small-signal approximation in order to optimize the performance of all the links. It is observed that the most limiting factor degrading the SNDR performance is changed, and the fundamental power is seen to increase more compared with the power of third-order intermodulation (IM3) plus noise due to the optical preamplifier. Thus, SNDR can be improved with respect to the case of a nonoptical preamplifier. For the preamplifier gain of 20 dB and noise figure of 3 dB, an increase of about 24 dB in optimum SNDR is accessible. In addition, the optimum DC bias phase shift is found to be insensitive to the preamplifier gain and noise figure, while the optimum SNDR is sensitive to the preamplifier gain and noise figure.

In this paper,on the basis of the costas OPLL configuration,costas OPLL mathematical model and phase noise were showed,then the bandwidth,linewidth and optical power splitting ratio were then analyzed and computed.All these results in this thesis can provide theoretical supportment for intersatellite coherent optical communication system.