低相噪振荡器的锁频电路模型  

Modeling of the frequency-locking circuit in a low phase noise oscillator

作　　者：杨非[1] 齐宁华[1] 孙忠良[1] 

机构地区：[1]东南大学毫米波国家重点实验室,南京210096

出　　处：《东南大学学报（自然科学版）》2010年第3期446-448,共3页Journal of Southeast University：Natural Science Edition

基　　金：国家自然科学基金委员会创新研究群体科学基金资助项目(60921063)

摘　　要：为了有效地改善振荡器相位噪声指标,研究了传输式锁频电路.分析了传输式锁频电路的工作原理,并完成了该类型电路模型的设计;建立了鉴频电路的传输模型,推导出表征锁频电路幅频特性的关系式,即鉴频灵敏度;分别考虑输入功率Pin及环路中谐振器端口耦合系数β的变化对于鉴频灵敏度的影响;最后利用鉴频电路传输方程H和鉴频灵敏度S,导出了振荡器的相位噪声表达式,利用该模型便于分析影响相噪指标的因素,所得结论与文献结论吻合较好.基于所建立的鉴频电路模型得出传输式锁频电路设计准则:提高输入功率Pin以及提高电路端口耦合度β,可取得更高的鉴频灵敏度,从而提高振荡器相位噪声性能.The transmission frequency locking circuit is studied here to improve the oscillator phase noise performance.The principle of the transmission frequency locking circuit is presented and the design of the circuit model is accomplished.First,a frequency discriminator circuit＇s transmission model is established,and the amplitude-frequency formula is derived,which is called discriminator sensitivity.Pin and β＇s influence to the performance of the discriminator sensitivity are both considered.Finally,the oscillator＇s phase noise is simulated by using the transmission function H and the discriminator sensitivity S,and the result fits well with the literature.Based on the frequency discriminator circuit＇s transmission model,the design criterion of the circuit is derived.When the input power Pinand coupling coefficient β are increased,the discriminator sensitivity can be increased simultaneously;finally,the oscillator＇s phase noise performance is improved.

关 键 词：相位噪声 振荡器 锁频电路 模型 

分 类 号：TN752.5[电子电信—电路与系统]