Heterologous Signal Separation Technology Design And Research Phase Power Amplifier System

Power amplifier has been widely used in the modern tele-communication systems, and its main function is to amplify the modulated signal to the desired power without deteriorating the signal quality, so that the antenna can transmit the signal efficiently. Therefore, the power amplifier plays a crucial role in the tele-communication system. Due to the requirement of the commercial application and academic research, high linearity and high efficiency has become a hot issue. There are three approaches for power amplifier linearity improvement, which are feed-back, feed-forward and out-phasing.This thesis firstly represents the advantages and disadvantages of these three methods, and then discusses the out-phasing power amplifier system for its high linearity and high efficiency simultaneously. The main component of out-phasing power amplifier is the signal components separator (SCS), and it can be realized by both the analog and digital methods. Up until now, with the great development of the LSI technology, the SCS based on the DSP technique has become increasingly feasible. This thesis focuses on two DSP algorithms with detailed discussions about their theoretical basis, and then verifies their performances under the ADS simulation environment with three different kind of modulated signals. Furthermore, the gain and phase imbalance phenomenon of the upper and lower path, which have a remarkable negative influence on the performance of the ultimate signal is also simulated in this thesis. The simulation result shows that the out-phasing power amplifier system can provide the better linearity and higher efficiency simultaneously, and is feasible to be achieved by the DSP algorithm.