基于载波抑制单边带调制的微波光子本振倍频上转换方法  

Microwave photonic frequency up-converter with LO doubling based on carrier suppression single-sideband modulation

作　　者：许家豪 王云新[1,2] 王大勇 周涛[3] 杨锋 钟欣 张弘骉 杨登才 Xu Jia -Hao;Wang Yun -Xin;Wang Da -Yong;Zhou Tao;Yang Feng;Zhong Xin;Zhang Hong -Biao;Yang Deng -Cai(College of Applied Sciences,Beijing University of Technology,Beijing 100124,China;Beijing Engineering Research Center of Precision Measurement Technology and Instruments,Beijing University of Technology,Beijing 100124,China;Science and Technology on Electronic Information Control Laboratory,Chengdu 610036,China)

机构地区：[1]北京工业大学应用数理学院,北京100124 [2]北京市精密测控技术与仪器工程技术研究中心,北京100124 [3]电子信息控制重点实验室,成都610036

出　　处：《物理学报》2019年第13期139-147,共9页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:61871007,61771438,51477028);北京市青年拔尖创新人才(批准号:CIT&TCD201504020)资助的课题~~

摘　　要：提出了一种基于载波抑制单边带调制的微波光子本振倍频上转换方法.通过将本振信号加载在马赫-曾德尔调制器上产生±1阶本振边带,利用光纤光栅进行边带分离,将–1阶本振边带作为载波输入双平行马赫-曾德尔调制器进行二次调制.中频信号通过90°电桥加载在双平行马赫-曾德尔调制器上,并使其工作在载波抑制单边带调制状态.最后将输出的中频单边带调制信号与光纤光栅反射的+1阶本振单边带信号进行合路拍频,即可获得频率为2wLO+wIF的上变频信号.为了验证该方法的有效性,搭建了上变频链路并进行了性能测试,实验结果表明链路的输出光谱和频谱较为纯净,经过单边带调制后的光谱杂散抑制比达到了22.5 dB,产生的本振倍频上转换信号的杂散抑制比达到了23.6 dB,系统的无杂散动态范围达到了96.1 dB·Hz2/3.该本振倍频上转换方法可有效降低对本振信号的频率需求,并且产生的上转换信号纯净度较高,为光载无线通信、光控相控阵雷达等系统中的高频发射提供了有效途径.Frequency up-converter as an essential component of the transmitter,which is used to implement the frequency up-conversion by mixing a low-frequency intermediate frequency(IF)signal with a local oscillator(LO)signal.However,only the 1st-order sideband of the LO signal and the IF signal are used in the tradtioanal microwave photonic up-converser,thus the frequency of the up-conversion signal is wLO+wIF.In this case,an LO with a higher frequency is needed for generating a high-frequency up-converted signal.In order to reduce the frequency requirement of the LO signal,the high-order LO singals or secondary modulation can be used to achieve high-frequency up-conversion.A microwave photonic up-converter with LO doubling based on carrier suppressing single-sideband modulation is proposed based on the cascaded structure of a Mach-Zehnder modulator(MZM)and a dual-parallel Mach-Zehnder modulator(DPMZM).The MZM is driven by an LO signal biased at the minimum transmission point for carrier suppressing double-sideband(CS-DSB)modulation.A fiber Bragg grating(FBG)is used to separate the+1st-order from-1st-order of the LO signal.The-1storder of LO signal is then sent to a DPMZM for the secondary modulation,and the carrier suppressing singlesideband(CS-SSB)modulation is realized in order to generate the-1st-order of the IF signal by using an electrical 90°hybrid coupler.The modulated IF signal is then combined with the+1st-order LO signal reflected by the FBG and sent into the photodetector(PD)to implement the photoelectric detection.The upconverted signal with a frequency of 2wLO+wIF can be detected by a PD.The experimental results show that the spur suppression ratio of the optical spectrum and the up-converter signal reach 22.5 dB and 23.6 dB,respectively.The spurious-free dynamic range of the system is 96.1 dB·Hz2/3.The proposed system can effectively reduce the frequency requirement of LO signal,and the purity of the electrical spectrum is largely improved which benefits from the CS-SSB modulation.The proposed microwave p

关 键 词：微波光子 频率上转换 载波抑制单边带调制 

分 类 号：TN761[电子电信—电路与系统] O572.31[理学—粒子物理与原子核物理]