【摘要】 从D. B. Leeson的反馈振荡器模型出发,分析了有载品质因数Q_L对振荡器相位噪声的影响。依据Takashi Ohira的无源二端口网络Q_L表达式,推导出西勒振荡电路的Q_L电路元件参数之间的量化关系,进一步分析出影响西勒振荡器有载品质因数Q_L的关键元器件参数。在此基础上引入虚拟仪器技术,利用LabVIEW与Multisim的联合仿真开发振荡器相位噪声分析平台,将影响振荡器相位噪声的关键元器件设置为输入控件,运用LabVIEW强大的数据分析功能测量关键元器件参数不同取值下的Multisim仿真输出波形的功率谱密度。将多次仿真分析结果记录保存后,合并显示在同一"X Y图"控件中,从而直观动态的展示电路元器件参数变化对振荡电路的相位噪声特性的影响。该平台不仅可以用于验证理论分析结果,也为振荡器相位噪声的分析及低相位噪声振荡器的设计提供了新思路和新方法。更多还原

【Abstract】 The influence of the loaded quality factor Q_L on oscillator phase noise was analyzed from the feedback oscillator model of D. B. Leeson. According to the Q_L formulation for two-port passive network of Takashi Ohira, the quantification relationship between Q_L and Seiler oscillator circuit component parameters was deduced, and the key component parameters affecting Q_L of the Seiler oscillator were further analyzed. The virtual instrument technology was adopted to develop an oscillator phase noise analysis platform. The key component that affect the phase noise were set as input controls, and the power spectral densities under different values were measured, respectively. Then we recordel and saved multiple experimental measurement results, combined them in the same "X Y Graph" control. In this way, the influence of the changes in the parameters of the circuit components on the phase noise characteristics of the oscillating circuit can be intuitively and dynamically displayed. This platform can not only be used to verify the theoretical analysis results, but also provide new ideas and new methods for the analysis of oscillator phase noise and the design of low phase noise oscillators.更多还原