Study And Design Of Broadband High-efficiency Power Amplifier Based On GaN HEMT Device

With the rapid development of modern mobile wireless communication technology,the wireless communication technologies will become the past of 2G,3G and 4G,and the fifth generation mobile communication technology(5G)is quietly approaching.From generation to generation of mobile wireless communication technology,mobile communication systems need to meet compatible down,there has been resulted in demanding for the signals at different frequencies and different modulations(e.g.GSM 900 MHz,WCDMA,DCS 1800 MHz,PCS 1900 MHz,3.5GHz Wi Max and 5G).However,the power amplifier is the most important module of wireless communication system,and its broadband,output power and efficiency performance directly affects the quality of mobile wireless communication system.Based on the development of multi-mode and multi-frequency wireless communication system,This thesis researched and designed the broadband and high efficiency power amplifier circuit.The characteristics of the design of the power amplifier of multi-octave broadband,the first is a multi-octave broadband high efficiency power amplifier is designed.The optimal impedance regions of the active device was found by loadpull simulation.The Chebyshev multi-section matching transformers are employed to design input or output matching network with extended bandwidth,thus achieving multi-octive broadband high efficiency power amplifier at the frequency band of 0.8-4.0 GHz(133% fractional bandwidth).High efficiency wideband power amplifier was designed and experimented,the measured results shown a drain efficiency(DE)of 54.20%-73.73% with an output power of 39.5-42.9 d Bm and the gain of 9.4-12 d B.For a 5MHz WCDMA signal,the adjacent channel leakage ratio of the power amplifier reaches-27.2 d Bc without Digital Pre-Distortion at center frequency 2.4 GHz.The frequency range of this thesis covers modern wireless communication systems like Wi Fi,GSM,3G,4G and 5G etc.The second paragraph of the broadband high efficiency power amplifier presents a modified high-efficiency power amplifier configuration with extended bandwidth.Two section impedance transformation are employed to reduce impedance transformation ratio and to achieve broadband output impedance match,the complex impedances of active device are to match a real impedance(20?),and a Klopfenstein impedance taper is accomplished to match to 50? in second impedance transformation.High efficiency broadband power amplifier is designed and experimented based on Ga N HEMT CGH40010 F,the measured results of continuous wave large signal shown a drain efficiency(DE)of 55.42%-80.47% with an output power of 40.54-42.72 d Bm from 0.8 GHz to 2.5 GHz(103% fractional bandwidth),and the power gain higher than 10.21 d B.The adjacent channel leakage ratio(ACLR)of the power amplifier reaches-34.5 d Bc at the frequency 1.8 GHz without linearization technique using 5MHz WCDMA modulated signal.In this thesis,aim at power amplifier output power,drain efficiency,working bandwidth and linearity performance indexes detailed theoretical analysis and engineering design,and through theoretical analysis and design of this thesis is very good finished in to ensure that the power amplifier output power,efficiency and linearity expand bandwidth conditions.