Suppression of low-frequency noise using discrete component chopping noise suppression circuit for space inertial sensor drive voltage amplifier

The space inertial sensor represents a pivotal component of the space gravitational wave detection apparatus, whereas the test mass (TM) it contains serves as a pivotal reference for space gravitational wave detection. The actuation circuit maintains the TM at a fixed position within the space inertia sensor. The Drive Voltage Amplifier (DVA) of the actuation circuit introduces low-frequency noise that directly affects the accuracy of gravitational wave detection at the mHz frequency. Therefore, it is of great significance to suppress low-frequency noise in the DVA. This study analyzes the noise modeling of the DVA in the actuation circuit and points out that the low-frequency noise of the DVA is mainly 1/f noise. A set of chopping noise suppression circuits is designed to greatly suppress the noise floor of the DVA under the premise of ensuring the functionality of the circuit. Based on chopping technology, a set of chopping noise suppression circuits is designed, and a prototype circuit was constructed for experimental analysis. The test results show that the noise floor of the DVA circuit at 1 mHz had been reduced from 21.7 ± 1.51 μV √Hz−1 to 1.35 ± 0.22 μV √Hz−1, which notably diminished the noise floor of the DVA circuit and can be applied to the design of future actuation circuit for the space inertial sensor.