Design Of A Novel And Low Distortion Switching Power Amplifier

Power amplifier is the facility which amplifies the input reference signal to the required signal. There have two basic requirements. One is that the output signal can correspondence match with the input signal. Too is to say low distortion. The other is that the dissipation of the power amplifier is small. Too is to say high efficiency. Power amplifier is widely used in industry, aviation electronics, communication system, home entertainment and etc.The switching power amplifier has the advantage of its high efficiency. But the distortion introduced by switching power amplifier is typically larger than in their liner counterparts due to intrinsic nonlinearity of switching power amplifier. One of the effective methods to enhance the switching power amplifier fidelity is to increase the main circuit switching frequency, but this way will add the power consumption and descend the efficiency, It will limit the development of the switching frequency's increase and the applying field of the switching power amplifier. So how to keep both high efficiency and low distortion is the emphases of the study of the switching power amplifier.To solve the problem that switching power amplifier has low efficiency and high distortion, This thesis design a novel switching power amplifier. The main circuit adopts full-bridge inverter circuits with the use of the power devices MOSFET, Control circuit mainly adopt low distortion signal generator MAX038 and monopole SPWM modulated circuit. There is no dead time in the system, and the full-bridge has the advantages of differential output by nature. So the total harmonic distortion of the switching power amplifier was deeply reduced Experimental results show that the scheme design is reasonable, simple control, and easy to realize.The main work of this thesis is as follows:(1) Analysing the basic principle and structure of the switching power amplifier and the difference between traditional power amplifier and the switching power amplifier . (2) Analysing the reasons for causing the distortion in theory and simulating analysis, questing the method to solve these problem.(3) Analysing circuit design and parameters selection of various parts of the switching power amplifier(4) A prototype is designed to conduct experiments. It reached the design requirements...