Research On Class F Power Amplifiers Applied To Communication Base Stations

As human beings gradually move toward the information age,people's requirements for mobile communications are becoming higher and higher,such as signal coverage,high-speed Internet access,etc.These requirements are inseparable from the development of communication base stations.Increasing the coverage of the signal requires that the transmitting system of the base station have a high output power to transmit the signal to a long distance,and having a high-speed Internet access experience requires a wide bandwidth of the communication base station.However,the transmitting system of the base station is the most energy-consuming part of the whole system,so it is necessary to consider the stability and energy consumption conditions of the transmitting system,and the RF power amplifier plays an important role in the base station transmitting system,and its performance determines the performance of the entire launch system.This is precisely the requirement that we design a broadband high-power high-efficiency power amplifier.Because Class F power amplifier has excellent performance,this thesis designs a Class F power amplifier for communication base station based on Class F power amplifier theory.The thesis firstly consults a large number of literatures on the design of RF power amplifiers at home and abroad,and analyzes the research done by researchers on Class F power amplifiers.Secondly,this thesis introduces some of the basic theories about designing RF power amplifiers in detail,including the theoretical derivation of telegraph equations for transmission lines,as well as indicators for evaluating the performance of amplifiers.Next,the theory of the Class F power amplifier is analyzed,and the equation of the drain voltage and current waveform in the Class F power amplifier will be deduced.the harmonic control network using lumped parameters and the harmonic control network using distributed parameters are introduced.The program provides theoretical support to designs.This thesis uses different innovative methods to design two power amplifiers:The first amplifier is applied to 4G communication base station,which is based on a GaN HEMT device designed a power amplifier in 1.5-2.6 GHz.The design uses a radial microstrip line to design a wideband harmonic control network,and the gate source parasitic compensation circuit reduces the influence of input harmonics on output power and efficiency,so that the second harmonic impedance is zero in the design frequency band.The third harmonic impedance is infinite.The measured results show that the drain efficiency is maintained at 65%-76.93%,the output power is 43.37-45.63 dBm,the gain is greater than 10 dB,and the second and third harmonic suppression levels are maintained at-15.56 to-26.09 dBc and-19.38 to-40.54 dBc,respectively,which meets the design requirements..The second power amplifier is applied to the 5G communication base station.A low-pass filter matching circuit is used to design a power amplifier with a frequency of 2.6-3.6 GHz.The measured results show that the drain efficiency is 66%-69%,the output power is 40.68-41.6 dBm,the gain is above 10 dB,which meets the design requirements.The performance of the power amplifier designed by these two design methods is greatly improved,including output power,efficiency and bandwidth.This provides a new design method,which is for the design of power amplifiers for communication base stations in the future.