Research On RF Broadband Switching Power Amplifier

Power amplifiers(PA)are one of the most critical components of wireless transmission base stations.Their output power,bandwidth,efficiency,linearity and operating temperature have a great impact on the entire wireless transmission system.Compared with existing standards such as the fourth generation mobile communication system(4G),the fifth generation mobile communication system(5G)can achieve higher data rates,lower delays and more application scenarios.This poses a huge challenge to the performance of the power amplifier.With the continuous evolution of wireless communication standards,the spectrum resources are decreasing,the modulation method is more complicated,and broadband,high efficiency and high linearity power amplifiers have become new research trends.The bandwidth of traditional switching-mode power amplifier is too narrow,which limits the application of the switching-mode power amplifier.In this paper,,Continuous-mode theory was proposed to solve the bandwidth limitation of traditional switch mode PA.It provides high efficiency in wide bandwidth by properly introducing impedance control of the second-order harmonic and the third one.And the design of a plurality of broadband high-efficiency switching-mode power amplifiers is realized from the voltage and current waveforms of the power amplifier.First of all,the practicality of the inverse class-E power amplifier in the S-band was successfully verified,and the power-added efficiency(PAE)was more than 60% in the range of 400 MHz with the center frequency of 3.5 GHz.Then,combining the impedance space of two power amplifiers,a method for simultaneously realizing two power amplifier working modes in the same working bandwidth is proposed..And using Cree's gallium nitride(Ga N)transistor CGH40010 F to achieve continuous class-F and inverse class-F mode-transfering power amplifier in the bandwidth of 2.4-4.2GHz,the designed amplifier's drain efficiency is 55%~82%.Digital predistortion technology improves the ACPR of the amplifier by approximately 6d B.Finally,on the basis of the impedance solution space of continuous class-F and hybrid continuous class power amplifiers,the method of further expanding the impedance design space of the power amplifier is proposed.The design realizes an extended hybrid continuous power amplifier that spans multiple octaves.The efficiency of the power amplifier is greater than 55% in the range of 0.2-2.3 GHz,which greatly expands the bandwidth of the power amplifier.