压电矢量传感器的低噪声设计

针对压电矢量传感器的低噪声设计问题,建立了基于压电敏感器件、悬挂结构、前置放大电路及电缆的同振式矢量传感器等效自噪声分析模型;结合敏感器件的低噪声设计、悬挂结构对自噪声的影响以及前置放大电路低噪声匹配等内容提出了一种低噪声设计方法。设计了低噪声矢量传感器样机,研制了自噪声测量平台并对样机进行了测试。结果表明:样机的等效噪声声压谱级达到了55.5 dB/√Hz2@200 Hz,低于同频率Knudsen零级海况下海洋环境噪声;测试结果与设计结果相符,验证了低噪声设计方法的有效性,也为压电矢量传感器的低噪声设计提供了理论依据。

Low-noise design of piezoelectric vector sensor

For low-noise design of the piezoelectric vector sensors, an equivalent self-noise analysis model of co-vibrating vector sensor system was established which including piezoelectric accelerometer, suspension structure, pre-amplifier and cables. A low-noise design method was proposed combining the low-noise design of the piezoelectric accelerometcr, the influence of the suspension structure on self-noise, and the low-noise matching of pre-amplifier with piezoelectric accelerometer together. A low-noise vector sensor prototype was designed and fabricated, a self-noise measurement platform was developed as well. The prototype was measured in the platform. The equivalent noise pressure level of the prototype reached 55.5 dB/√Hz@200 Hz, which was lower than the Knudsen ambient noise level of Sea State 0 (SS0). Tile experiment results were well in agreement with prediction, which showed that the design method was valid, and provided a theoretical basis for low noise design of piezoelectric vector sensor.