Simple and high-efficiency super class-A power amplifier

The invention discloses a power amplifier with the application of a bias current compensating voltage source circuit of a complementary transistor. The design is to amplify the class-A signal of a big current under the condition of simple and small current bias. The method comprises the following steps of: along with the increasing of the output current, improving the bias current at the final-stage of the power amplifier in real time, compensating the reduced bias current of one power tube caused by current output, thereby continuously amplifying the class-A signal. The power amplifier works in a high-efficiency class-A state when under big current, and the bigger the output current is, the higher the efficiency is. The core bias circuit achieves the requirement only by combining two complementary transistors, so that the circuit is simple and clear; a main signal amplifying loop is not changed at all in comparison to the traditional circuit, and the innovation is intensively expressed on a constant voltage