Chinese Journal of Quantum Electronics, Volume. 36, Issue 6, 709(2019)
Terminal noise filtration of hydrogen clock signal after transmission
The low phase-noise and high frequency-stability 10 MHz hydrogen clock signal (HCS) is the indispensable microwave frequency reference for physics experiments of precision measurement. After transmitted over a certain distance, the phase noise and short-term stability of the HCS will be downgraded due to the disturbance of the external electromagnetic noise and vibration. A scheme to filter the terminal noise of the HCS after transmission is introduced, which reduces the phase noise and improves the short-term stability of the HCS. The scheme is based on phase-locking of an oven-controlled crystal oscillator (OCXO) to the HCS, the phase noise and frequency stability of the reference signal at shorter than 1 s is defined by the OCXO, while the long-term stability follows the HCS. After the filtering scheme, the power of the HCS is amplified from -4.4 dBm to 5 dBm, the terminal phase noise background of the HCS is reduced about 10 dB, and all disturbance higher than 1 Hz are eliminated. The system can dramatically purify the HCS without changing the laboratory hydrogen clock and the HCS transmitting network, and then the accuracy of precision measurement experiment is improved.
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YAO Bowen, SUN Huanyao, CHEN Qunfeng. Terminal noise filtration of hydrogen clock signal after transmission[J]. Chinese Journal of Quantum Electronics, 2019, 36(6): 709
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Received: Mar. 5, 2019
Accepted: --
Published Online: Dec. 6, 2019
The Author Email: Bowen YAO (1783324062@qq.com)