High Efficiency High Linearity Rf Power Amplifier In The Research And Design

The upcoming deployment of China’s indigenous TD-LTE mobile communicationsystem make the corresponding research on its RF module necessary, which as anintegral part of all wireless communications, has a critical impact on the performance ofthe overall system. Radio frequency power amplifiers are an essential part of the RFmodule, and its efficiency, power gain and linearity directly influence the coveringrange, power consumption and bit-error-rate (BER) of the LTE base station or handsets.Based on these backgrounds, a high efficiency and high linearity power amplifier for theLTE application is designed in this paper.Currently the ways to improve efficiency of power amplifiers include reducing theconduction angle, driving the PA into switch mode, Doherty topology, EnvelopeElimination and Restoration etc. The method adopted in this paper is using the Class-Fpower amplifier for its low cost and relatively simple circuit topology.Since the transistor is driven into saturation in Class-F mode, it suffers from poorlinearity as its output signal is distorted in terms of amplitude. In order to reducedistortion, particularly the third-order intermodulation of the output signal, thepredistortion technique is used to improve the PA’s linearity.The contents of the paper are summarized as follows:Chapter1gives a brief introduction to the development of wirelesscommunications and its accompanying requirements for the PA design;Chapter2mainly deals with the techniques in designing matching networks underlarge-signal input and linearization methods;Chapter3discusses the working modes for power amplifiers and their efficiencies;Chapter4covers the design of the class-F amplifier;Chapter5covers the linearization by predistortion;Chapter6summarizes the dissertation and proposes the future work.