X-band Mmic Power Amplifier

The design of pHEMT MMIC monolithic power amplifier is presented.The main content of this thesis contains that the evolved history,the advantages of MMIC and the theory of Two-Dimension Electronic Gas(2DEG)about the pHEMT are retrospected;The operation principle of pHEMT and the small-signal and large-signal model parameter are introduced; At last,the detail of the designed MMIC power amplifier are given.Based on the Win cooperation 0.15μm GaAs pHEMT process and ADS,a X-band MMIC power amplifier is designed.The first stage with gate width of 4×75um will give about 15dB gain for the small-signal.The second stage has four times gate width of the first stage,and it will give the small-signal gain further while driving the next stage.The third stage have eight cells,each of cell have the gate width of 4×100um,this stage mainly supply the drive power for the last stage.In the last stage,there are sixteen cells that with each gate width of 8×100um.All the stages are fed by double DC supplying;and the first three stages work at class-A operation for minimal distortion.;the last stage works at class-AB operation for more power out and efficiency.The Wilkinson networks are used to make the power combing and dividing networking.After optimized,the power amplifier has 24dB small-signal gain with input and output VSWR less than 2,The output power at 1dB gain compression are more than 37.3dBm and the max Pout is more than 38.02dBm from 8 to 11 GHz.Input and output ports all match to 50ohm.The chip size is 5.18mm×6.97mm.In conclusion,analysis of the simulation results satisfied all requirements.