Research On The X-band GaAs PHEMT MMIC Power Amplifier

The high-speed development of 5G telecommunication and Internet of Things,calls for the dramatically increased use of RF microwave front-end circuits and module.MMIC is attractive for its ability to satisfy the high integration,low consumption,miniaturization and high reliability requirements in the microwave integrated circuits and systems of the military and civilian electronic devices.A MMIC power amplifier is one of the most important components in RF microwave front-end transmitting chain,and its performance has direct influence on the quality of signal emission.In view of the MMIC power amplifier applied in the X-band of phase control radar,navigation communication and satellite communication,this paper presents a wideband three-stage power amplifier operating in 8~12GHz frequency range based on 0.5?m AlGaAs/InGa As/GaAs pHEMT process.The MMIC design flow and the whole design scheme,the selection of HEMTs dimension,DC bias technique,matching network design and stability improvement strategies have been described in detail.Finally,a wideband three-stage power amplifier has been achieved to meet the system performance requirement.The testing result showed that the proposed power amplifier was operated in 8~12GHz frequency range,its small signal gain was greater than 21 dB,gain flatness was less than 2dB;Its input and output return loss were less than-10dB;Its saturated output power was greater than 26dBm;Its maximum power added efficiency was more than 30%.This paper also has made analytical algorithm and numerical calculation for the channel temperature of transistor.According to the process technology information provided by the manufacturer,a finite element software,Comsol Multiphysics,has been used to do the thermal steady-state solution on the geometric modeling of final stage HEMTs and acquire the HEMTs' thermal distribution data.The simulation result showed that the steady state peak temperature was 122?.The numerical analysis method proposed in this paper can be used to evaluate the peak temperature of the HEMTs quickly and effectively in the reliability analysis of MMIC design.