Power Amplifier Design Based On Series Of Continuous Modes

Power amplifier plays an important role in communication system.With the development of communication technique,various modulation types will increasingly be complicated,shortage of radio spectral resource getting exiguouser.High efficiency,broadband and good linearity are inevitable trends for power amplifier in wireless communication system.However,Continuous theory offered an efficient way for highly efficient and broadband power amplifier design.On the other hand,Doherty structure helps deal with high PAPR signals caused by complex modulation mode.This thesis has improved the continuous theory based on a waveform engineering method.Firstly,resistive second harmonic impedance has been introduced into the design of series of continuous inverse modes,a resistive-reactive series of continuous inverse modes power amplifier has been fabricated with a drain efficiency higher than 67%across a bandwidth of the second octave.Secondly,the continuous mode theory has been further improved and a theory on resistive-resistive series of continuous class-F/F^-1modes have been proposed,which offers a solution for the overlap between the fundamental and third harmonic impedances in broadband application over the second octave.A resistive-resistive series of continuous class-F/F^-11 modes power amplifier has been fabricated to verify the above theory.Finally,the author proposed a method dealing with the power leakage of Doherty power amplifier at back-off power,in which the small signal output impedance characteristic of the auxiliary PA has been extended to a broadband over one and a half octave.A single-pole triple throw?SP3T?switch has been utilized in bias circuit to offer passageways with attenuation for AC signal at different frequency.In this way,the bandwidth of high small-signal output impedance of class-C power amplifier could be extended,the power leakage of Doherty power amplifier can be controlled at back-off power.