一种汽泡型铷原子频标伺服电路中的相位稳定性问题

Phase Stabilities of the Servo Circuit in a Vapor Cell Rubidium Atomic Frequency Standard

着重讨论了汽泡型铷原子频标伺服电路中T型选频电路和RC移相电路的相位稳定性,分析了它们的附加相移波动影响整机频率稳定度的机理。为改进原子频标的性能,提出了一种用现场可编程门阵列(FPGA)实现对同步检测参考信号进行数字移相的技术。该基于FPGA的伺服电路的温度附加不稳定度为1×10-12/℃。

The phase stabilities of the T-type frequency selector and RC phase-shift circuit, which are applied to the servo circuit of a vapor cell rubidium atomic frequency standard, are discussed mainly, and the mechanism how the additional phase variations coming from the two circuits influence the frequency stability of a rubidium standard is analyzed. In order to improve the performance of the atomic frequency standard, a new method of realizing a digital phase shift based on FPGA （field programmable gate array） for the synchronous detection reference signal is presented. The additional frequency instability caused by the servo circuit based on FPGA is 1×10^-12/℃, relating to the environment temperature.