新型星载超宽带微波光子变频技术

Broadband Microwave Photonic Frequency Conversion Technology for Satellite Payloads

摘要:

传统的星载变频通道存在易受电磁干扰、动态范围受限、带宽瓶颈等不足,将微波光子技术引入卫星通信系统中,可克服电域信号变频的局限性,提升星载变频通道的性能。文章提出了一种基于并联马赫-增德尔调制器(MZM)与相干接收的宽带微波光子变频技术, 通过采用相干接收方法,能够实现较好的共模噪声抑制,并降低谐波失真的影响,同时结合抑制载波调制方式所带来的优势,有效改善了变频无杂散动态范围等指标。通过实验验证,其杂散抑制比优于60dB,无杂散动态范围优于100dB·Hz2/3,为新型星载微波光子变频方案设计、实际应用提供了必要的理论依据与技术支撑。

Abstract:

The conventional frequency conversion of satellite payloads in electronic domain has the drawbacks such as susceptible to electromagnetic interference, limited spur-free dynamic range (SFDR), as well as narrow band. The introduction of microwave photonic into satellite communication system has shown many interesting advantages, overcoming the limitations of signal frequency conversion in electric domain and improving the performance of the on-board frequency channel. A broadband microwave photonic frequency conversion technology based on parallel Mach-Zehnder modulator (MZM) and balanced coherent heterodyne detection is proposed in this paper. Better common mode noise suppression and reduced harmonic distortions were achieved by using balanced coherent heterodyne detection. While combining the advantages brought about by the suppression of carrier modulation, the SFDR of the frequency conversion system were significantly improved. A spur suppression ratio better than 60dB and a SFDR better than 100dB·Hz2/3 in microwave photonic frequency conversion system is proposed and experimentally demonstrated. Essential theoretical basis and technical support are provided for the new scheme of microwave photonic frequency conversion of satellite payloads.