四阶声低通滤波光纤水听器的声压灵敏度频响特性

Frequency response of fourth-order acoustic low-pass filtering fiber-optic hydrophones

对四阶声低通滤波光纤水听器的声压灵敏度频响特性进行了详细的理论和实验研究.在已有的低频集中参量模型中引入了一个机械声阻,用于描述系统的机械损耗,从而得到了改进的声学等效电路.相位频响特性对于光纤水听器的阵列应用非常重要,关系到阵列的波束形成效果,进而影响系统定位、识别与跟踪目标的能力,因此在分析幅度频响特性的同时研究了相位频响特性.仿真分析了各主要参量对声压传递函数的影响,得到了一些对声低通滤波光纤水听器设计具有重要指导意义的结论.实测声压灵敏度频响曲线与仿真结果基本一致,较好地验证了理论分析的正确性.四阶声低通滤波光纤水听器的研制成功,对于提高光纤水听器阵列的抗高频混叠性能具有重要的作用.

Response properties of the fourth-order acoustic low-pass filtering fiber-optic hydrophones are investigated theoretically and experimentally.A mechanical acoustic resistance,which is used to describe the system s mechanical loss,is introduced into the previous lumped parameters model of the hydrophone,and an improved acoustic equivalent circuit is given.Phase frequency response is an important parameter for the hydrophone array applications.It has great effect on beamforming,which affects the abilities of locating, discerning, and tracking targets. Therefore, the phase response peroporties is studied with the amplitude response peroperties. Some results, which are instructive for designing of acoustic low-pass filtering hydrophone, are obtained by numerical simulation. The measured rsponse curves are in good agreement with the simulation results, which verifies the correctness of the theory and the model. The fourth-order acoustic low-pass filtering fiber-optic hydrophones are useful for improvement of the anti-aliasing ability of modem sonar arrays.