一种微波倍频方案在小型化铷钟的应用

A Method for Microwave Frequency Multiplication in Miniaturized Rubidium Atomic Clocks

为了进一步实现铷原子钟的小型化,介绍了一种小型化铷钟微波倍频电路的设计及初步实现情况.该倍频电路利用数字锁相环将晶体振荡器输出的10 MHz参考信号直接倍频至6 834.68XX MHz,并对该信号进行2FSK调制.受调制的微波信号经过功率调整后馈入物理系统微波腔中,激励铷原子基态超精细能级跃迁.这种微波调频倍频电路方案具有体积小,调试简单的特点.将该电路用于小型化铷钟,初步测试结果表明,其短期频率稳定度可以达到1.8×10-11τ-1/2的水平.

A microwave frequency multiplier is introduced in this paper,which may be used to further miniaturize rubidium atomic clocks.A digital phase-locked loop （PLL） technique was used in the microwave frequency multiplier to transform the 10 MHzsignal from VCXO to a 6 834.68XX MHz signal.After binary frequency shift keying （2FSK） modulation and power optimization,the microwave signal was fed into the microwave cavity of the physics package.This multiplication scheme makes the circuit board smaller and the debugging process easier.The circuit with this multiplier was implemented and used in miniaturized rubidium clocks.Preliminary test showed that the short term frequency stability achievable was 1.8 × 10-11 τ-1/2,