环形压控振荡器的噪声分析

Analysis of Phase Noise in Ring Voltage Controlled Oscillator

在振荡器的设计中,为了得到更高性能,分析其相位噪声是十分重要的.利用Razavi对具有普遍意义的品质因数的定义将Leeson针对LC振荡器提出的相位噪声模型应用到环形振荡器上对其进行噪声分析.文中以一个2GHz环形振荡器为例,采用TSMC0.25μm CMOS工艺参数,用Cadence的spectre仿真器进行仿真.电源电压为2.5V,偏离中心频率1MHz处的相位噪声为-86.6dBc/Hz.仿真的结果与噪声模型所的结果基本吻合.

In order to obtain higher performance, the analysis of phase noise in oscillators plays an important part in designing VCO. Based on the define of quality factor by Razavi, we employ the phase noise model of LC VCO by Leeson to investigate the phase noise of ring oscillator. We analyse a 2 GHz ring VCO,the design was simulated by cadence spectre. Under TSMC 0. 25 μm CMOS process. The supply voltage is 2. 5 V, the VCO has a phase noises of -86.6 dBc/Hz at a 1 MHz offset. Results derived from the proposed model are in agreement with those from simulation.