应用于相干布居囚禁原子钟的低相位噪声微波频率综合器

Low Phase Noise Microwave Synthesizer for Coherent Population Trapping Atomic Clock

相干布居囚禁(CPT)原子钟作为微波原子钟的一种类型,由于不需要微波谐振腔即可实现微波探询,可极大降低体积和功耗,从而实现芯片级、低功耗的原子钟。CPT原子钟性能指标的主要限制因素之一是微波综合器的相位噪声,为了提升CPT原子钟的性能,研制了一种应用于CPT原子钟的低相位噪声频率综合器。实验结果表明,频率综合器在200 Hz处的绝对相位噪声为108 dBc/Hz。微波综合器由于Dick效应对原子钟频率稳定度的限制为8.2×10^(-14),可以完全满足CPT原子钟的性能指标要求。此频率综合器也可更广泛地用于其它高性能微波原子精密测量系统以及计量标准器。

Atomic clock based on coherent population trapping(CPT)could interrogate the atoms without microwave cavity,which significantly reduce the volume of the physical package.One of the main limitations of CPT clock is the phase noise of the microwave synthesizer.Here a low phase nosie microwave synthesizer for CPT clock system is demonstrated.The absolute phase noise of the microwave synthesizer achieved-108 dBc/Hz at 200 Hz offset frequency.The frequency stability limitation of CPT clock with this synthesizer is calculated to be 8.2×10^(-14)with Dick effect formula.This low phase noise microwave synthesizer could be also applied in other types of precision measurement system and standards based on atoms.