基于分数阶时域Talbot效应的宽带射频信号实时频谱分析  

Real-time Spectrum Analysis of Wideband RF Signals Based on Fractional Temporal Talbot Effect

作　　者：杨波 赵雷 杨淑娜 池灏 YANG Bo;ZHAO Lei;YANG Shuna;CHI Hao(School of Information and Control Engineering,China University of Mining and Technology,Xuzhou 221116,China;School of Communication Engineering,Hangzhou Dianzi University,Hangzhou 310018,China)

机构地区：[1]中国矿业大学信息与控制工程学院,徐州221116 [2]杭州电子科技大学通信工程学院,杭州310018

出　　处：《光子学报》2024年第4期139-145,共7页Acta Photonica Sinica

基　　金：国家自然科学基金(Nos.62101168,61975048,61901148)。

摘　　要：提出一种基于分数阶时域Talbot效应的宽带射频信号实时频谱分析方案。该方案基于采样和色散结构,实现射频信号频率到光脉冲时间间隔的映射。通过预先经过一个满足分数阶时域Talbot距离的色散元件,光脉冲在采样之前的重复频率发生倍增。利用分数阶时域Talbot效应,可以显著提升系统的频率测量带宽。实验结果表明,利用9阶分数阶时域Talbot效应,实现29.7 GHz带宽内单音和双音射频信号的实时频谱分析。数值仿真结果进一步验证了该方案能够有效分析频率快速变化的宽带射频信号。该方案结构简单、带宽大、可实时处理,有望应用于电子对抗、宽带雷达、认知无线电等场景。To enhance the bandwidth and real-time capabilities of Radio Frequency(RF)spectrum analysis,the optical real-time Fourier transform method has been proposed.The optical real-time Fourier transform method based on the temporal Talbot effect has the advantage of a simple structure by using optical pulse sampling and dispersion delay structure.However,its frequency measurement bandwidth is limited by the optical pulse's repetition rate.Addressing this limitation,a real-time spectrum analysis scheme of wideband RF signals based on the fractional temporal Talbot effect is proposed and demonstrated.Based on the sampling and dispersion structure,the scheme realizes the mapping of the RF signal frequency to the optical pulse time interval.At the same time,the repetition rate of the optical pulse before sampling is multiplied by passing through a dispersive element satisfying the fractional Talbot distance in advance.The frequency measurement bandwidth of the system can be significantly improved by using the fractional Talbot effect.A proof-of-concept experiment is carried out to test the performance of the proposed scheme.The repetition period of the optical pulse is set to 151.5 ps,that is,the repetition frequency is 6.6 GHz.Each pulse has a Gaussian shape and the full width at half maximum of the pulse is approximately 30 ps.Dispersion compensation fiber is used to provide dispersion for the system.The total dispersion value of the two sections of dispersion is about 3650 ps2,which is about 0.1%different from the theoretical result.The RF signal to be measured is generated by a RF signal generator.The output optical signal is converted into an electrical signal by a 40 GHz bandwidth photodetector and recorded by a sampling oscilloscope with a bandwidth of 50 GHz.Comparing the experimental results under integer-order,3rd-order fractional,and 9th-order fractional temporal Talbot conditions,it is verified that the measurement frequency bandwidth of the system increases with the order of the temporal Talbot effect.Real-tim

关 键 词：频谱分析 光子辅助射频频谱分析 实时傅里叶变换 TALBOT效应 分数阶时域Talbot效应 

分 类 号：TN29[电子电信—物理电子学]