Study On The Technology Of Reconfigurable And Continuous Class-BJ Power Amplifier

With the rapid development of wireless communication technology,there is a big challenge for the underlying radio frequency(RF)devices.As one of the RF core devices,RF power amplifier(PA)needs to adapt to multi-mode communication systems.However,it is difficult to take care of all the working frequencies for the current multi-mode and multi-frequency RF PA technology in the case of frequency dispersion.In order to improve this situation,a combination of continuous PA technology and reconfigurable technology is adopted to design the amplifiers.Continuous PA has the characteristics of high efficiency and wide bandwidth,and reconfigurable PA has the characteristics of small power consumption and large flexibility.Now the two technologies are combined and their advantages are complementary.On one hand,the problem of bandwidth is overcome and high power added efficiency(PAE)is gotten,on the other hand,the advantages of multi-mode and multi-frequency PA are greatly given play to,at the same time,the volume,cost and power dissipation of PA is reduced.Base on the combination mentioned above,further study of continuous class-BJ PA is focused on.The specific work in the thesis is as followed:1.The influence of transistor's parasitic parameters on the design of continuous class-BJ PA is systematically summarized.The design space of continuous classBJ PA and the trend of optimization impedance in design space are analyzed.At the same time,the design method of harmonic control amplifier,the design idea of bias circuit and the principle of load pull technology are also introduced.2.A kind of continuous class-BJ PA is designed.Different from traditional design method which fails to fully consider and reflect the trend of impedance change throughout the spectrum,a new design method which considers harmonic control and fundamental wave match at the same time is proposed to decrease parasitic effect of transistors,output matching network with concise and compact structure is realized in the frequency band of 1.8-2.2GHz.Through experimental verification,this new kind of matching network structure can create the basic and secondary impedance environments for continuous class-BJ PA,and can achieve 50-60% efficiency.3.A kind of reconfigurable continuous Class-BJ PA is designed.Learning from the design idea of tunable filter for reference and considering the characteristics of the changes of fundamental wave and second harmonic impedance,a new kind of reconfigurable continuous class-BJ PA is successfully designed through improving output matching network.Through simulation and experimental verification,this reconfigurable continuous class-BJ PA can realize the bandwidth and center frequency reconfigurable near the center frequency of 1.3GHz.According to the test,the efficiency is between 40.2% and 58.1% when the frequency range is 0.95-1.65 GHz in the case of reconfigurable bandwidth.In the case of reconfigurable central frequency,when the frequency range is 0.87-1.61 GHz,the efficiency is around 50.7%.