Square Kilometre Array Telescope--Precision Reference Frequency Synchronisation via 1f-2f Dissemination.
The Square Kilometre Array (SKA) project is an international effort to build the world's largest radio telescope, with a one-square-kilometre collecting area. In addition to its ambitious scientific objectives, such as probing cosmic dawn and the cradle of life, the SKA demands several revolutionary technological breakthroughs, such as ultra-high precision synchronisation of the frequency references for thousands of antennas. In this report, with the purpose of application to the SKA, we demonstrate a frequency reference dissemination and synchronisation scheme in which the phase-noise compensation function is applied at the client site. Hence, one central hub can be linked to a large number of client sites, thus forming a star-shaped topology. As a performance test, a 100-MHz reference frequency signal from a hydrogen maser (H-maser) clock is disseminated and recovered at two remote sites. The phase-noise characteristics of the recovered reference frequency signal coincide with those of the H-maser source and satisfy the SKA requirements.
Joint Institute for Measurement Science, Tsinghua University, Beijing 100084, China.|State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instruments, Tsinghua University, Beijing 100084, China.
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Wang
Joint Institute for Measurement Science, Tsinghua University, Beijing 100084, China.|Department of Physics, Tsinghua University, Beijing 100084, China.
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Zhu
Joint Institute for Measurement Science, Tsinghua University, Beijing 100084, China.|State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instruments, Tsinghua University, Beijing 100084, China.
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Gao
Joint Institute for Measurement Science, Tsinghua University, Beijing 100084, China.|Department of Physics, Tsinghua University, Beijing 100084, China.
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Bai
Joint Institute for Measurement Science, Tsinghua University, Beijing 100084, China.|State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instruments, Tsinghua University, Beijing 100084, China.
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Dong
Joint Institute for Measurement Science, Tsinghua University, Beijing 100084, China.|State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instruments, Tsinghua University, Beijing 100084, China.|Department of Physics, Tsinghua University, Beijing 100084, China.|National Institute of Metrology, Beijing 100013, China.
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Wang