用于CPT原子频标的高性能小型合成源设计

根据相干布居囚禁原子频标对合成源的要求,利用直接数字频率合成器激励锁相环实现了高稳定度、高分辨率、快跳频速度、低相位噪声、小体积的小步长扫描合成源。比较应用于相干布居囚禁原子频标的合成源方案,介绍直接数字频率合成器激励锁相环频率合成器的基本原理,简述用AD9954和ADF4350所设计高性能小型合成源的具体实现方法,并通过仿真优化得到最佳的输出性能。采用DDS与PLL相结合的混合结构设计的合成源,综合了DDS和PLL各自的优点,具有优良的技术性能,进一步提高了CPT原子频标标准输出频率的性能。同时,达到了设计小型化的要求,有利于CPT原子频标的便携式应用。

Design of High-Performance and Miniature Synthesized Source for Coherent Population Trapping Atomic Frequency Standard

In accordance with the requirement to synthesized source by the Coherent Population Trapping（CPT） atomic frequency standard,a synthesized source,with the characteristics of high stability,high resolution,fast frequency hopping speed,low phase noise,miniature,and small scanning step,is realized through direct digital frequency synthesizer（DDS） exciting phase-locked loop（PLL） frequency synthesizer.Several schemes of the synthesized source for CPT atomic frequency standard are compared.The basic principle of DDS exciting PLL and the practical method of high-performance and miniature synthesized source implemented using AD9954 plus ADF4350 are introduced.At last,the best performance of the output signal is obtained by optimizing the simulation result.The synthesized source using the combination structural design combines the advantages of DDS and PLL,has excellent technical performance,and further improves the output signal of the CPT atomic frequency standard.Moreover,the overall design comes up to the miniaturized requirement,and is favorable to portable application of the CPT atomic frequency standard.