An Adaptive Broadband Active Impedance Matching Network for Underwater Electroacoustic Transduction System

Since the power supply is limited in ships, the impedance matching network is essential for a high-power underwater electroacoustic transduction system. However, the existing impedance matching networks can barely achieve full impedance matching under a wide frequency change range. This article proposes a shunt active impedance matching network (SAIMN) to achieve adaptive broadband impedance matching (up to 400 Hz) for increasing power utilization from a power amplifier to the transducer. First, the load impedance characteristic and operation principle of SAIMN are introduced mathematically. Second, the parameter design method is provided to improve impedance matching performance. After that, a compound control strategy is presented to control the power amplifier and proposed SAIMN. Finally, the simulation and experimental results validate the effectiveness of the proposed SAIMN and its control strategy. The results clearly show that the proposed SAIMN can adaptively match load impedance for the different loads in a broadband frequency range. The power factor of the power amplifier is significantly improved, and the current stress of the switching device is significantly reduced with the proposed SAIMN.