Research On Wideband Power Amplifiers Based On Simplified Real Frequency Technology

Wireless communication technology is developing rapidly,and China has been a leader in the field of 5G communication technology.Radio Frequency Front-end(RFFE)is a vital part and PA is the main energy consumption unit of the RFFE.Its property is related to the communication and comprehensive performance of the whole system.The research on PAs mainly focuses on efficiency,output power,bandwidth and other indicators.Since wireless communication systems transmit non-constant envelopment signals,linearity becomes one of the important indicators of PAs.In the paper,the technical background,feature and current situation of PA are described.On account of introducing the theory of PA,the bandwidth extension method of PA is studied deeply.There are many ways to extend the bandwidth of PA,among which simplified real frequency technology(SRFT)is a circuit synthesis method that uses software to calculate the matching circuit parameters after setting the optimization target based on the port impedance measurement data of multi-frequency points in the wider band.SRFT is suitable for the design of wideband matching circuit in engineering.In this paper,based on the SRFT,the broadband PA has been studied and two broadband high-efficiency PAs with relative bandwidth over 135% have been designed.The test results are consistent with the theory.Two broadband amplifiers are designed respectively from the perspective of bandwidth and efficiency improvement by using simplified real frequency technology as follows:1.A multi-frequency range broadband power amplifier based on simplified real frequency method is proposed.A loss-free structure is established for two-port network of PA's matching circuit,and the TPG is optimized.In order to verify its effectiveness,a 0.5-2.8 GHz power amplifier is designed and manufactured.The measurements display that the output power is 40-42.8d Bm,which achieves good results.Gain and efficiency meet the requirement.2.In-depth study and discussion of simplified real frequency technology,analysis of the optimal impedance value variation rule at the transistor load term,and put forward a broadband efficient power amplifier based on the improved simplified real frequency algorithm.By improving the optimization objective and error function in the simplified real frequency method,the best impedance of multiple points is summarized and the output matching circuit of the PA is optimized to enhance the bandwidth of working.The test results in the frequency band of 0.5-2.7 GHz not only maintain the original bandwidth level,but also achieve the maximum drain efficiency of 75%.