基于频谱整形的光学微波波形信号产生的研究

Research on optical microwave waveform signal generation based on spectrum manipulation

由于传统电学方式产生的微波信号容易受到电子瓶颈的束缚,获得高重复频率的波形信号较难,而微波光子学中的光生微波技术具有高带宽、抗电磁干扰、体积小重量轻等优点,在生成微波波形信号方面有着独特的优势。因此,提出了一种结构简单,可灵活调谐的光学微波信号产生方法,并且所产生的波形信号格式具有可重构的优势。该方法根据傅里叶级数理论,利用相位调制器对光波进行调制,通过滤波器对光载波和边带进行整形,进而获得光学微波波形信号。结果表明该设计方案可行,能够产生重复频率为10 GHz的三角波、方波以及一对相反极性的脉冲序列,具有生成任意波形的潜力以及可集成化的应用价值。

Microwave signals generated by traditional electrical methods are easily constrained by electronic bottlenecks, it is difficult to obtain the waveform signal with high repetition frequency. The photo-generated microwave technology in microwave photonics has the advantages of high bandwidth, anti electromagnetic interference, light volume and small weight in generating microwave signals. In this paper, a simple, flexible and reconfigurable optical microwave waveform signal generation method is proposed. According to Fourier series theory, this method uses a phase modulator to modulate the light wave, and the optical carrier and sideband are shaped by a filter, then the optical microwave signal is obtained. The results show that the design scheme is feasible and can generate a triangular waveform with a repetition frequency of 10 GHz, a square waveform and a pair of pulse sequences with opposite polarities. The scheme has the potential to generate arbitrary waveform and can be integrated.