基于随机非线性微分方程的振荡器相位噪声研究  

Analysis of Phase Noise in Oscillators Based on Nonlinear Stochastic Equation

作　　者：林蔚然[1] 来金梅[1] 章倩苓[1] 任俊彦[1] Omar Wing 

机构地区：[1]复旦大学专用集成电路与系统国家重点实验室,上海200433

出　　处：《固体电子学研究与进展》2004年第1期86-91,共6页Research & Progress of SSE

基　　金：上海市 AM基金"CMOS.RFIC设计方法及技术研究"项目资助(编号 :0 0 0 2 )

摘　　要：根据振荡器电路的时变非线性特性 ,运用一种通用的相位噪声理论 ,通过对噪声源随机过程建模 ,求解具有严格数学意义的随机非线性微分方程 ,得到一个常数 c来描述时间抖动和频谱扩散。分别用基于随机非线性微分方程和线性时变的方法求解 ,结果表明线性时变得到的相位噪声频谱在基频附近分布的能量之和超过载波能量 ,在物理意义上有一定不足 ;而文中的相位噪声分析结果表明相位噪声只改变能量的分布并不能使能量显著增加 ,得到的结果为设计电路时减少相位噪声影响提供了思路。Phase noise is of crucial importance in electric circuits. In this paper, we apply a generic phase noise theory to obtain an exact nonlinear stochastic equation for perturbed oscillator, then solve it and get a scalar constant c which is sufficient to describe jitter and spectral properties. By computing phase noise in a Colpitts oscillator using this theory and the time varying linearization method respetively, we get the result that the PSD has a finite value at carrier frequency and the total carrier power is preserved despite spectral spreading due to noise, whereas the result by the time varying linearization method exceeds the carrie power. Furthermore, by computing the noise contribution of each noise source, we illustrate how to reduce phase noise in circuit design.

关 键 词：振荡器 相位噪声 时间抖动 随机非线性微分方程 洛仑兹能量谱 

分 类 号：TN752[电子电信—电路与系统]