A Hybrid Impedance Matching Network for Underwater Acoustic Transducers

Abstract

The underwater acoustic transducer (UAT) is an electro-acoustic conversion device, which is a nonlinear reactive load. An impedance matching network is usually added between the power amplifier and the UAT. This paper proposes a hybrid impedance matching network (HIMN) combining passive impedance matching and active impedance matching. Compared with the conventional matching, this method can improve the matching frequency range and reduce matching delay. Firstly, the impedance model of the UAT is proposed, and the matching principle of the HIMN is analyzed. On this basis, the parameter design method is given within the required frequency range. Then, to reduce the matching delay of the system, a control method based on reference signal synchronization is proposed, including the reference compensation voltage calculation method and model prediction control (MPC) with two-step prediction. Finally, the simulation and experimental hardware in loop (HIL) results are given, which verify the effectiveness of the proposed HIMN and control algorithm proposed in this paper. The results show that the proposed HIMN can achieve a wider matching frequency range and shorter matching delay.