具有稳定环路带宽功能的多模分数频率综合器  

Multi-mode fractional-N synthesizer with a stabilized loop bandwidth

作　　者：冯焱[1] 罗阳 陈贵灿[1] 

机构地区：[1]西安交通大学电信学院,陕西西安710049 [2]西安华讯微电子有限公司,陕西西安710075

出　　处：《西安电子科技大学学报》2013年第5期119-123,193,共6页Journal of Xidian University

摘　　要：针对多模式频率综合器在模式转换中的稳定性问题,提出了一种以分频比校正电荷泵电流来稳定环路带宽的方法,使系统在各个模式下环路带宽的变化均保持在很小的范围内.该电荷泵校正电路应用于一个多模式分数频率综合器,该频率综合器在3个定位系统的7个模式下均能稳定可靠工作.仿真结果表明：在7种模式下,归一化环路带宽ICP KVCO/ωVCO的变化范围为-3.3％～3.3％.该频率综合器在每种模式下的带内相位噪声均小于-93 dBc/Hz,在带外频偏1MHz处,相位噪声均小于-119 dBc/Hz.各个模式锁定时间均小于24 μs,在1.8V电源电压下,功耗为15.21 mW.To solve the problem of stability of the multi-mode frequency synthesizer during mode transitions,a method of stabilizating the loop bandwidth is presented by means of calibrating the charge pump current according to the divider ratio.The method makes the variation of the loop bandwidth to be kept within a smaller range at different division ratios.A multi-mode fractional-N synthesizer adopting the method can work stably in seven modes of three positioning systems.Simulation results show that the variation of normalized ICP KVCO/ωVCO in seven modes is in the range of-3.3％ and 3.3％.For each mode,the in-band and out-of-band phase noises are not larger than-93 dBc/Hz and-119 dBc/Hz,respectively.The setting time is less than 24 μs.The total power consumption is 15.21 mW at 1.8 V voltage supply.

关 键 词：全球定位系统 分数频率综合器 环路带宽 相位噪声 

分 类 号：TN432[电子电信—微电子学与固体电子学]