Li Guozheng, Hao Tengfei, Li Wei, Li Ming
Opt Express. 2021 Oct 25;29(22):36977-36987. doi: 10.1364/OE.442723.
Optoelectronic oscillators (OEOs) are promising for radar, communication and electronic countermeasure systems. Among them, frequency-scanning OEOs with wide instantaneous bandwidth are needed for many advanced applications. In this work, we demonstrate a novel system to generate bandwidth-doubled linearly chirped microwave waveforms (LCMWs) based on bandwidth superposition using a Fourier domain mode-locked OEO (FDML OEO). In the proposed system, bandwidth-doubling is achieved by re-modulating the generated LCMW of the FDML OEO onto a frequency-scanning optical carrier signal with the help of an external Mach-Zehnder modulator. LCMWs with wide frequency scanning instantaneous bandwidth of 10 GHz are experimentally obtained. Meanwhile, these LCMWs are tunable in an ultra-wide frequency range from 1 to 39 GHz. Moreover, they are with high frequency sweep linearity of 0.5%. Our work presents a simple method to generate tunable wide-band LCMWs for potential microwave sources.
光电振荡器（OEO）在雷达、通信和电子对抗系统中具有广阔的应用前景。其中，许多先进应用需要具有宽瞬时带宽的频率扫描OEO。在这项工作中，我们展示了一种基于傅里叶域锁模OEO（FDML OEO）利用带宽叠加来生成带宽加倍的线性调频微波波形（LCMW）的新型系统。在所提出的系统中，通过外部马赫-曾德尔调制器将FDML OEO生成的LCMW重新调制到频率扫描光载波信号上，实现带宽加倍。实验获得了频率扫描瞬时带宽为10 GHz的宽LCMW。同时，这些LCMW在1至39 GHz的超宽频率范围内是可调谐的。此外，它们具有0.5%的高频扫描线性度。我们的工作提出了一种生成可调谐宽带LCMW的简单方法，可用于潜在的微波源。
