A Smooth Switching System of Atomic Clock Based on Real-time Tracking Technology

Abstract

The invention discloses an atomic clock smooth switching system based on real-time tracking technology, and relates to the technical field of the time frequency generation and maintenance of a satellite-borne atomic clock. The atomic clock smooth switching system comprises a dual-mixing time difference circuit, a FPGA module, a frequency synthesizer circuit, an electronic switch and an analog phase-locked loop, wherein the FPGA module comprises a DDS module, a phase difference measurement module, an infinite pulse response digital filter module and a fault detection module; on the basis of the DDS module and the dual-mixing time difference circuit, an error signal is filtered and purified through the infinite pulse response digital filter to obtain a frequency control word of the DDS with fine-tuned frequency control; the equality of the tracking period and the measurement is guaranteed through a real-time tracking algorithm without measuring the frequency and the phase in time-sharing, and the frequency and phase jump indexes before and after the switching are ensured.

Description

technical field [0001] The invention relates to the technical field of time-frequency generation and maintenance of satellite-borne atomic clocks, in particular to a stable atomic clock switching system based on real-time tracking technology. Background technique [0002] The Beidou-2 satellite uses the 10MHz frequency of the atomic clock as the satellite standard time reference signal. The reference frequency synthesizer of the time-frequency generation and maintenance equipment receives the 10MHz signals output by the two atomic clocks, and generates two 10.23MHz reference signals using the main and standby frequency synthesis links. frequency. Select one of them through the electronic switch to enter the phase-locked loop to lock the high-stable crystal oscillator, providing a stable and reliable 10.23MHz reference frequency for navigation satellites. [0003] When the atomic clock or frequency synthesizer of the on-board working path fails, the 10.23MHz signal will be d...

AI Technical Summary

Problems solved by technology

The former cannot guarantee the stability of the output signal when the working clock fails, and the latter, within the time interval between two trackings, the phase difference between the main and standby clocks will drift with the frequency residual of the main and standby clocks, reducing the phase jump performance before and after switching

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