带前放压电水听器噪声建模及低噪声设计方法

Noise Modeling and Low-Noise Design Method of Piezoelectric Hydrophone Pre-Amplifier

为满足低频压电水听器工作需求,针对带前置放大器压电水听器自噪声优化问题,理论推导二端口网络等效噪声模型,利用LTSPIC建立SPICE模型对关键器件进行噪声仿真,并基于结型场效应管设计制作低噪声放大电路。对设计的放大器及带前放水听器自噪声测试表明,放大器等效输入噪声为8.48 nV/√Hz@1 kHz,1/f噪声拐点约为350 Hz,优于现有集成运放式放大器;带前放水听器噪声谱级为33.577 dB@1 kHz,其噪声谱级低于零级海况噪声谱。

In order to meet the working requirements of low-frequency piezoelectric hydrophones,to address the self-noise optimization problem of piezoelectric hydrophones with pre-amplifiers,the equivalent noise model of two-port network is theoretically derived,and the SPICE model is established using LTSPIC to simulate the noise of key components.The low noise amplifier circuit is designed and manufactured based on the junction field effect transistor.The self-noise test on the designed amplifier and the hydrophone with pre-amplifier shows that the equivalent input noise of the amplifier is 8.48 nV/√Hz@1 kHz,and the inflection point of 1/f noise is about 350 Hz,which is better than that of the existing integrated operational amplifier;the noise spectrum level of the hydrophone with pre-amplifier is 33.577 dB@1 kHz,which is lower than the zero-order sea state noise spectrum.