Design And Simulation Of Novel GaN HEMT Power Amplifier

With the development of 5G technology,wireless communication technology has been applied into every aspect of our life.As the major part of wireless communication system,the performance of power amplifier directly affects the overall performance of wireless communication system.With the increase of the output power and working frequency band of the power amplifier,higher working efficiency has become the goal pursued by people.How to improve the efficiency of power amplifier has become the focus of research on power amplifiers,under the call of “Energy conservation,Emission reduction,green and efficient”.This paper proposes a design goal of an internal matching power amplifier working at Sband 2.0GHz~2.5GHz with an output power greater than 50 d Bm(100W),and explores the design method of high-efficiency power amplifier.Firstly,this paper compared several mainstream power amplifier devices.It is found that the third-generation semiconductor material Ga N,has smaller parasitic parameters,higher electron mobility and other characteristics,by comparison.Ga N HEMT has good efficiency performance in the S-band,so Ga N HEMT is chosen as the power amplifier device of power amplifier.Then the device model of Ga N HEMT is analyzed,several key model parameters of Ga N HEMT are simulated and verified by using EE_HEMT model in ADS software.The influence of key model parameters on efficiency is analyzed,finally parameters of the device is selected.In the design of power amplifier,the influence of the harmonics are fully considered in order to improve the efficiency.A compact LC matching structure is used to match the impedance to the optimal impedance space.Meanwhile,in order to broaden the bandwidth,a multisection impedance matching structure is used in the impedance matching network.The designed power amplifier realized the balance of high efficiency and broadband by using a compact structure.Through a power divider with impedance transformation function at the input and output terminals,the impedance matching network transformation ratio could be reduced.The capacitance and inductance in the matching networks are realized by high dielectric constant substrate and bonding wire.The measured results show that it achieves the power output of above 50 d Bm,the power added efficiency of above 70% at the frequency range from 2.0GHz to 2.5GHz.Compared with other S-band power amplifiers published in the literature,the performance of efficiency is outstanding,which verifies the feasibility of the design method.