50 MHz低噪声Colpitts石英晶体振荡器设计  

Design of 50 MHz Colpitts Quartz Crystal Oscillator With Low Phase Noise

作　　者：王艳[1] 崔莹 WANG Yan;CUI Ying(School of Electrical Engineering and Information,Southwest Petroleum University,Chengdu 610500,China)

机构地区：[1]西南石油大学电气信息学院,四川成都610500

出　　处：《压电与声光》2018年第3期349-351,共3页Piezoelectrics & Acoustooptics

基　　金：四川省科技厅应用基础基金资助项目(2014JY0208)

摘　　要：该文在振荡器Leeson模型的基础上分析了有载品质因数(Q_L)对振荡器相位噪声的影响,且通过分析Colpitts振荡电路得到了其Q_L的表达式,明确了Q_L与电路参数的精确关系。并用安捷伦ADS软件对50 MHz Colpitts晶体振荡器的相位噪声进行了仿真,根据仿真结果在提高Q_L的基础上设计了一晶体振荡器样机,样机采用AT切三次泛音、49U电阻焊封装的晶体谐振器,其无载品质因数(Q_0)为1.45×10~5。经测试得到其相位噪声指标优于-107dBc/Hz@10Hz、-134dBc/Hz@100Hz和-152dBc/Hz@1kHz。实验结果表明,基于提高Q_L设计低相噪晶体振荡器的方法是可行的。The influence of loaded quality factor （QL） on the oscillator phase noise is analyzed on the basis of Leeson model in this paper, the expression of QL is obtained from the analysis of Colpitts oscillator circuit and the exact relationship between QL and the circuit parameters is clarified. The phase noise of the 50 MHz Colpitts crystal oscillator is simulated with Agilent ADS software. Based on the simulation results and improving the loaded quality factor Q L , a prototype crystal oscillator is designed. The prototype uses the AT-cut 3rd overtone crystal resonator with 49U resistance welding package, its unloaded quality factor（Q0）is about 1.45×10^5. The measured phase noise are better than -107 dBc/Hz@10 Hz, -134 dBc/Hz@100 Hz and -152 dBc/Hz@1 kHz. The experimental results show that it is feasible to design low phase noise crystal oscillators on the basis of improving QL .

关 键 词：Leeson模型 有载品质因数 相位噪声 Colpitts晶体振荡器 ADS仿真 

分 类 号：TN75[电子电信—电路与系统]