数模混合GHz级频率综合器下变频模块设计

介绍了一种应用于GHz级高速频率合成器的数模混合下变频模块.采用了高速射频双模预分频器与数字逻辑综合生成的可编程吞脉冲分频器相结合的设计方法.双模预分频实现了高速低抖动低功耗,双模预分频器工作在除8状态输出133MHz频率时,均方差抖动小于2ps;可编程吞脉冲分频器算法灵活、设计复用性强,该算法可以灵活运用到许多复杂频率综合系统.相比较而言,该设计获得了更好的高频电路性能与设计复用性.

Design of Down Scalers in Mixed-Signal GHz Frequency Synthesizer

An optimized method is presented to design the down scalers in a GHz frequency synthesizer. The down scalers are comprised of dual modulus prescaler (DMP) and programmable & pulse swallow divider,different methods of high frequency analog circuit and digital logical synthesis are adopted respectively. Using a DMP high speed,lower jitter and lower power dissipation are obtained,and output frequency of 133.0MHz of the DMP working at divide-by-8 shows an RMS jitter less than 2ps. The flexibility and reusability of the programmable divider is high;its use could be extended to many complicated frequency synthesizers. By comparison,it is a better design on performance of high-frequency circuit and good design flexibility.