一种基于串联谐振腔的高性能光电振荡器  

An optoelectronic oscillator based on series resonance cavity

作　　者：黄港膑 王菊[1] 王文睿[1] 贾石[1] 于晋龙[1] 

机构地区：[1]天津大学电子信息工程学院,天津300072

出　　处：《物理学报》2016年第4期97-102,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:61427817;61405142);高等学校博士学科点专项科研基金(批准号:20120032130010)资助的课题~~

摘　　要：提出了一种利用串联谐振腔来抑制光电振荡器边模的方案.此方案中,在传统光电振荡器结构中加入无源微波谐振腔结构来提高滤波器的Q值.分析了该结构的基本原理,并与传统光电振荡器结构进行对比,此结构能有效提高边模抑制比.实验中产生了10 GHz的微波信号,所测得的边模抑制比达72 dB,单边带相位噪声为-122 dBc/Hz@10kHz.同时,利用锁相技术,振荡频率的稳定性得到了很大的改善,在3 h内漂移小于±4 Hz.该方案无需增加有源器件,保留了传统光电振荡器低相位噪声的优势,又有效抑制了边模,为光电振荡器的应用提供了一种新的方法.Commercial and military applications of microwave and millimeter-wave sources in aerospace, radar, navigation, and communication system require high spectrum purity and low phase-noise oscillators. The optoelectronic oscillator （OEO） emerges as an excellent low noise source that has attracted great attention in recent years. In this paper, a novel technique is proposed for single-mode selection in an optoelectronic oscillator, which uses a microwave cavity as the mode selector. It consists of a pump laser and a feedback circuit including an intensity modulator, an optical fiber delay lines, a photodetector, an amplifier, a filter and two drilling cables. The drilling cable is fabricated by drilling open holes on a coaxial cable using a drilling machine. By changing the radius of the drilling holes, the designed reflection coefficient can be obtained. By simulation, the constructed microwave resonator that consists of a filter and two drilling cables has a higher Q value and only the modes that satisfy the oscillation conditions of the loop will be selected. The basic principle is analyzed theoretically and experimentally. By comparing with traditional structure of OEO, it is shown that the novel structure can effectively improve the side-mode suppression ratio. In addition, the stability of the oscillation frequency is easier to control than the parallel structure. In this experiment, the output of a 10 GHz single-mode signal with a side-mode suppression ratio of 72 dB and a phase noise of -122 dBc/Hz@10 kHz from the carrier is obtained. Meanwhile, phase-lock techniques are used to compensate the drift of cavity length. Then the radio frequency （RF） stability of the oscillation frequency is measured using an RF spectrum analyzer, and the RF stability over 3 hours for the OEO is less than ±4 Hz. This scheme has the advantages of traditional OEO with low noise since no extra active devices are needed, and it suppresses the side-mode noise also effectively. In addition, this system is promising for the d

关 键 词：光电振荡器 边模抑制 微波谐振腔 稳定性 

分 类 号：TN753.2[电子电信—电路与系统]