The Power amplifier is one of the core components of the sonar transmitter. Regarding its special application environment in sonar transmitter, the amplifier circuit must have small size,low power consumption,high efficiency,high reliability and output power adjustment.The main job of this thesis is to design a continuously adjustable Class D power amplifier. At first, the classification of the power amplifier is discussed. According to the requirements, class D power amplifier is chosen as the main design....