微波通信用高稳定本振源的设计

Design of High Stable Local Oscillator for Microwave Communication

摘要: 光电振荡器(Opto-electronic Oscillator, OEO)由于具有超低相噪可作为本振应用于微波通信系统。本文针对当前OEO稳定性欠佳的问题，先用反馈回路对电光强度调制器的工作点进行控制，然后采用导频方法对振荡环路的稳定性进行控制，将一低频率的导频信号引入微波光链路、提取其相位偏差信息，然后反馈给OEO环路，最终实现了良好的稳定信号输出，其阿伦方差在1 s内约为2.7 × 10−12。

Abstract: Optoelectronic oscillator (OEO) can be used as local oscillator for microwave communication system because of its ultra low phase noise. In order to solve the problem of poor stability of OEO, the feedback loop was used to control the working point of the electro-optic intensity modulator, and the pilot method was also applied to control the stability of the oscillating loop, so the long-term stability has been obviously improved. A low frequency pilot signal was introduced into the mi-crowave optical link and its phase deviation information was extracted, then came back to the OEO loop, and a good stable signal output was achieved. Finally, the Allen variance was about 2.7 × 10−12 in 1 s.