针对高载频、宽调谐线性调频信号产生问题, 提出了一种并联MZM的载频8倍频线性调频信号光产生方法。首先利用并联MZM的边带选取特性来获取 ± 4阶边带, 然后结合外调制技术将抛物线波形加载在一个边带上, 使系统产生载频8倍频的线性调频信号。最后基于Optisystem软件进行了仿真实验, 产生了载频分别为40 GHz和48 GHz, 带宽为16 GHz的线性调频信号, 实验结果验证了该方法的可行性。所提方法对可为日益高频化的军用微波系统信号源提供一种解决思路, 展示了微波光子技术用于射频信号产生的巨大潜力。

To obtain linear frequency modulation (LFM) signal with high carrier frequency and large bandwidth, a photonic approach for generating LFM signal with frequency multiplication factor of 8 based on parallel MZMs is proposed. ±4 order sidebands are firstly obtained by modulating the parallel maximum-transmission Mach-Zehnder modulators (MZMs) with orthogonal radio-frequency signals, and then one sideband is selected out by optical filtering and is modulated in phase by parabolic waveforms. Thus, after frequency beating, LFM signal with octuple carrier frequency can be generated. Relative simulation experiments are conducted out by optisystem software to validate the effectiveness of the proposed method. The method we proposed can provide a solution of the signal source for military microwave systems while they become more and more high-frequency.