The Research Of Controlled Methods Of Adaptive Feedforward Power Amplifier

In the system of modern wireless communication, the transmission of information is developing toward multi-carrier, great-capacity and high-speed. This needs the RF components to provide higher linear in the systems of communication. Especially the linearity of power amplifier will affect the performance of the whole system. Feed-forward power amplifiers are more concerned by RF engineers because of its high linearity and stability, and the self-adaptive controlled method is the key technique in the system of the adaptive controlled feedforward linear power amplifier.This paper in the first chapter summarizes the domestic and foreign development of linear power amplifier systemically, and gives out the scheme of the adaptive controlled feed-forward linear power amplifier. In the second chapter the paper discribes the theories related to the adaptive controlled methods and the optimization algorithms used in the loop controll. And it introduces the basic application theories of the ARM at the end of the chapter. The third chapter as the main section of the paper clarifies the adaptive controlled theory of the feedforward amplifier in detail, and analyses and compares the two algorithms-- minimum power algorithm and minimum relativity algorithm, it also gives out the model of ADS of the feed-forward power amplifier and analyses the results of the simulation. In the fourth chapter the paper presents the design course of the hardware and the software of the ARM module and the chapter also gives out the test result of the two algorithms and the whole performance result of the feedforward amplifier. And the test result shows that the system satisfies the design requirement and the scheme was effective and practical.The self-adaptive controlled algorithm is one of the key techniques of adaptive control feed-forward power amplifier, and it influences the performance of the whole system. In the application, the algorithm under the different criterions should be optimized and can be more effective to use in the system.