Multi-frequency signal acquisition and phase measurement in space gravitational wave detection

Qiang-Tao Zhang; He-Shan Liu; Peng Dong; Pan Li; Zi-Ren Luo

doi:10.1063/5.0198104

Multi-frequency signal acquisition and phase measurement in space gravitational wave detection

Rev Sci Instrum. 2024 May 1;95(5):054501. doi: 10.1063/5.0198104.

Authors

Qiang-Tao Zhang^{1

2}, He-Shan Liu¹, Peng Dong², Pan Li¹, Zi-Ren Luo^{1

2}

Affiliations

¹ National Microgravity Laboratory, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China.
² School of Fundamental Physics and Mathematical Sciences, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310024, China.

PMID: 38743572
DOI: 10.1063/5.0198104

Abstract

To enhance the accuracy of phase measurement and to prevent tracking errors, it is crucial to effectively read the multi-frequency signal in space gravitational wave detection. In this paper, a novel signal acquisition method called the multi-frequency acquisition algorithm is proposed and implemented. Different from the traditional single-frequency acquisition, the signal characteristics of amplitude and frequency are both considered to better distinguish different frequency components. A phasemeter integrated with the acquisition method and narrow-bandwidth digital phase-locked loop is constructed for the method test and verification. The results show that the multi-frequency acquisition unit can capture all the frequencies of an input signal in several milliseconds. The precision is better than ±200 Hz under a low SNR (signal-to-noise ratio) of 0 dB. The phase noise can reach 2 µrad/Hz1/2 in the frequency range of 0.1-1 Hz and satisfy the requirement of the space gravitational wave detection in all frequency ranges.