Research And Design Of Multi-band High Efficiency Power Amplifier

Under the background of the coexistence of various communication standards,as an important part of RF communication front-end,it is urgent to expand the working frequency band of power amplifier.In this thesis,based on a deep understanding of the working principle of power amplifier,a new multi-band matching network is conceived,and a number of multi-band power amplifiers working in 2G-5G band are studied and designed.The superiority of the designed tri-band power amplifier is proved by comparing the relevant literatures at home and abroad.The main work of this thesis is as follows:1.A dual-band power amplifier topology is proposed.The power amplifier works in two frequency bands,2.5?2.7GHz and 3.5?3.6GHz,and adopts a dual-band matching network.The matching network firstly converts the input impedance to the real impedance,and then realizes the matching between the real impedance and the load impedance through an impedance matching structure equivalent to a quarter wavelength transmission line in dual-frequency band.Based on this matching network,a dual-band power amplifier is designed.The simulation results show that the power amplifier has high efficiency and high inter-band rejection.The test results show that the maximum drain efficiency of the power amplifier is 66.61% and 62.16%,and the maximum output power is 41.99 d Bm and 40.26 d Bm,respectively,and the amplifier has inter-band rejection.2.A tri-band high efficiency power amplifier topology based on ring matching structure is proposed.The power amplifier is connected in series with the fundamental wave matching structure by a novel ring harmonic control structure,which can control both the fundamental wave and the second harmonic in the high efficiency impedance space,so as to obtain high efficiency output.Simulation results verify its excellent frequency selection characteristics.The final test results show that the maximum drain efficiency of the power amplifier in three frequency bands(0.89?0.92 GHz,2.5?2.7GHz and 3.5?3.6GHz)is 67.35%,75.57% and 71.83%,respectively.The maximum output power is 40.61 d Bm,40.56 d Bm and 41.58 d Bm,respectively.The comparison of domestic and foreign related literature shows that the design has certain advantages in technical indicators.3.A tri-band power amplifier topology with high inter-band rejection is proposed.The power amplifier works in three frequency bands of 0.87?0.97 GHz,2.0?2.7GHz and3.5?3.6GHz,and adopts a novel tri-band matching network.The load source is used to draw the optimal impedance of the three central frequency points,and the conjugate impedance of the three optimal impedance is used as the input port impedance of the matching network.The impedance of the three input ports corresponds to the three central frequency points one by one.The S-parameter simulation is carried out to verify the tri-band matching network.The results show that the matching network produces frequency response at the central frequency point corresponding to the input port impedance,and has good frequency selection characteristics.The test results of the power amplifier designed with the matched network show that the maximum drain efficiency is 65.6%,66.3% and 65.1%,and the maximum output power is 40.2d Bm,41.9d Bm and 40.7d Bm,respectively.A comparison of domestic and foreign related literature shows that the design has certain advantages in bandwidth,inter-band rejection and operating frequency ratio.