School of Physics and Astronomy, Sun Yat-sen University, Zhuhai 519082, China.
DFH Satellite Co., Ltd., Beijing 100094, China.
Sensors (Basel). 2023 May 10;23(10):4611. doi: 10.3390/s23104611.
A temperature measurement subsystem (TMS) is a critical piece of infrastructure of the space gravitational wave detection platform, necessary for monitoring minuscule temperature changes at the level of 1μK/Hz1/2 within the electrode house, in the frequency range of 0.1mHz to 1Hz. The voltage reference (VR), a key component of the TMS, must possess low noise characteristics in the detection band to minimize the impact on temperature measurements. However, the noise characteristics of the voltage reference in the sub-millihertz range have not been documented yet and require further study. This paper reports a dual-channel measurement method for measuring the low-frequency noise of VR chips down to 0.1mHz. The measurement method makes use of a dual-channel chopper amplifier and an assembly thermal insulation box to achieve a normalized resolution of 3×10-7/Hz1/2@0.1mHz in the VR noise measurement. The seven best-performance VR chips documented at a common frequency range are tested. The results show that their noise at sub-millihertz frequencies can significantly differ from that around 1Hz.
温度测量子系统（TMS）是空间引力波探测平台的关键基础设施之一，对于监测电极室内 1μK/Hz1/2 量级的微小温度变化以及 0.1mHz 至 1Hz 的频率范围至关重要。电压基准（VR）是 TMS 的关键组成部分，必须在检测频段具有低噪声特性，以最小化对温度测量的影响。然而，亚毫赫兹范围内电压基准的噪声特性尚未得到记录，需要进一步研究。本文提出了一种用于测量 VR 芯片低频噪声的双通道测量方法，可测量低至 0.1mHz 的频率。该测量方法利用双通道斩波放大器和组装隔热箱，在 VR 噪声测量中实现了归一化分辨率为 3×10-7/Hz1/2@0.1mHz。测试了在常见频率范围内性能最好的七个 VR 芯片，结果表明，它们在亚毫赫兹频率下的噪声与 1Hz 左右的噪声有显著差异。
