The space gravitational wave detection aims to detect gravitational waves in the mHz band in order to study supermassive black hole mergers,galaxy evolution and the structure of the early universe.One of its core payl...The space gravitational wave detection aims to detect gravitational waves in the mHz band in order to study supermassive black hole mergers,galaxy evolution and the structure of the early universe.One of its core payloads is a transponder-type interstellar laser interferometer,designed to measure relative displacement changes at the pico-meter level.Among its components,phasemeter is tasked with extracting the phase and frequency of the interference signal.Currently,phase-locked loop(PLL)phasemeters are commonly employed.However,the second harmonic signal generated by the mixer can restrict both the dynamic range and phase measurement accuracy of the phasemeter.This paper analyzes the interstellar laser interferometer and the impact of the second harmonic signal on the phasemeter's performance.To address these challenges,a phasemeter incorporating a second harmonic signal filter is proposed.This new design mitigates second harmonic disturbances within the phasemeter's bandwidth by dynamically adjusting the filter's cutoff frequency to track the input signal frequency,thereby suppressing the second harmonic signal in real time.Theoretical and simulation analyses demonstrate that the proposed phasemeter with a second harmonic filter significantly enhances the dynamic range.Finally,experimental results verify that the phasemeter can achieve the tracking of sudden frequency changes up to4.8 MHz.展开更多
The mission to detect gravitational wave in space requires a not only sophisticated but also ultra-precise laser interferometric measurement system. Within a single spacecraft, tens of interferometric beat signals are...The mission to detect gravitational wave in space requires a not only sophisticated but also ultra-precise laser interferometric measurement system. Within a single spacecraft, tens of interferometric beat signals are generated at the same time and they also need to be processed simultaneously. In this paper, a multi-channel phasemeter which can parallelly process the signals is constructed. The test shows that a sensitivity of 2n grad/√Hz could be achieved in the frequency range of 0.1 to 10 Hz. We also utilize the phasemeter to evaluate the performance of a heterodyne laser interferometer.展开更多
基金the National Key Research&Development Program of China(Grant No.2022YFC2203901)the State Key Laboratory of Spatial Datum(Grant No.SKLSD2025-KF-03)+1 种基金Fundamental Research Funds for the Central UniversitiesSun Yat-sen University for the support。
文摘The space gravitational wave detection aims to detect gravitational waves in the mHz band in order to study supermassive black hole mergers,galaxy evolution and the structure of the early universe.One of its core payloads is a transponder-type interstellar laser interferometer,designed to measure relative displacement changes at the pico-meter level.Among its components,phasemeter is tasked with extracting the phase and frequency of the interference signal.Currently,phase-locked loop(PLL)phasemeters are commonly employed.However,the second harmonic signal generated by the mixer can restrict both the dynamic range and phase measurement accuracy of the phasemeter.This paper analyzes the interstellar laser interferometer and the impact of the second harmonic signal on the phasemeter's performance.To address these challenges,a phasemeter incorporating a second harmonic signal filter is proposed.This new design mitigates second harmonic disturbances within the phasemeter's bandwidth by dynamically adjusting the filter's cutoff frequency to track the input signal frequency,thereby suppressing the second harmonic signal in real time.Theoretical and simulation analyses demonstrate that the proposed phasemeter with a second harmonic filter significantly enhances the dynamic range.Finally,experimental results verify that the phasemeter can achieve the tracking of sudden frequency changes up to4.8 MHz.
基金The Scientific Equipment Development and Research Project of Chinese Academy of Sciences(Grant No.Y231411YB1)The Space Science Research Projects in Advance of Chinese Academy of Sciences(Grant No.O930143XM1)
文摘The mission to detect gravitational wave in space requires a not only sophisticated but also ultra-precise laser interferometric measurement system. Within a single spacecraft, tens of interferometric beat signals are generated at the same time and they also need to be processed simultaneously. In this paper, a multi-channel phasemeter which can parallelly process the signals is constructed. The test shows that a sensitivity of 2n grad/√Hz could be achieved in the frequency range of 0.1 to 10 Hz. We also utilize the phasemeter to evaluate the performance of a heterodyne laser interferometer.
