Abstract A simple scheme to generate a frequency and bandwidth-doubling dual-chirp microwave waveform based on a dual-polarization Mach–Zehnder modulator (DPol-MZM) is presented, and the influence of fiber chromatic dispersion during transmission is analyzed in detail. In this scheme, the lightwave is split into two beams in the DPol-MZM, and one beam is modulated via sub-MZM1 by the RF signal to generate two second-order sidebands along with the optical carrier, while the other beam is modulated via sub-MZM2 by a single-chirp microwave with single sideband modulation. By adjusting the angle between the PBC and the principal axis of Pol, the output lightwave from the DPol-MZM is linearized and the optical carrier is eliminated. After optical to electrical conversion, a dual-chirp microwave waveform with doubled carrier frequency and doubled bandwidth is generated. The generated waveform can effectively avoid the power fading caused by chromatic dispersion as it is transmitted through the fiber. According to the simulation, the ambiguity function and autocorrelation of the generated waveforms show that the generated dual-chirp microwave waveforms at 20 GHz with 4 GHz bandwidth have good performance even after 30km fiber transmission. The simulation results agree well with our theoretical prediction. The system has a simple structure, good reconfigurability and tunability, and is expected to use in the radar systems.

中文翻译：

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具有带宽和倍频的双线性调频微波波形的光子生成和传输

摘要 提出了一种基于双极化马赫-曾德调制器(DPol-MZM)产生倍频带宽双线性调频微波波形的简单方案，并详细分析了传输过程中光纤色散的影响。在该方案中，光波在 DPol-MZM 中被分成两束，其中一束通过 RF 信号通过 sub-MZM1 调制以产生两个二阶边带以及光载波，而另一束通过sub-MZM2 由单边带调制的单线性调频微波组成。通过调整 PBC 与 Pol 主轴之间的角度，来自 DPol-MZM 的输出光波被线性化并消除了光载波。光电转换后，生成具有双倍载波频率和双倍带宽的双线性调频微波波形。生成的波形可以有效避免在光纤传输过程中由于色散引起的功率衰减。根据仿真结果，生成波形的模糊函数和自相关性表明，生成的20 GHz、4 GHz带宽的双线性调频微波波形即使在30km光纤传输后也具有良好的性能。模拟结果与我们的理论预测非常吻合。该系统结构简单，具有良好的可重构性和可调性，有望用于雷达系统。生成波形的模糊函数和自相关性表明，生成的20 GHz、4 GHz带宽的双线性调频微波波形即使在30km光纤传输后也具有良好的性能。模拟结果与我们的理论预测非常吻合。该系统结构简单，具有良好的可重构性和可调性，有望用于雷达系统。生成波形的模糊函数和自相关性表明，生成的20 GHz、4 GHz带宽的双线性调频微波波形即使在30km光纤传输后也具有良好的性能。模拟结果与我们的理论预测非常吻合。该系统结构简单，具有良好的可重构性和可调性，有望用于雷达系统。