【摘要】 提出了一种部分补偿SigmaDelta调制器整形噪声的新方案.通过在鉴频鉴相器中的延迟时段向无源滤波器中注入补偿电流,最大可实现16dB的噪声补偿.与其他补偿方案相比,文中提出的方案相对简单和易于实现.特别设计了可变延迟的鉴频鉴相器和补偿电流源,并给出了行为级和电路级的仿真结果.更多还原

【Abstract】 A novel method to partially compensate sigma-delta shaped noise is proposed.By injecting the compensation current into the passive loop filter during the delay time of the phase frequency detector(PFD),a maximum reduction of the phase noise by about 16dB can be achieved.Compared to other compensation methods,the technique proposed here is relatively simple and easy to implement.Key building blocks for realizing the noise cancellation,including the delay variable PFD and compensation current source,are specially designed.Both the behavior level and circuit level simulation results are presented.更多还原