Design And Implementation Of RF Power Amplifier

At present,mobile communications,satellite navigation,RFID radio communication technology has been rapid development,the related application penetrated into many aspects of human life,especially got unprecedented development in the financial,medical,education,transportation and other fields.Radio frequency power amplifier is a very important part in the whole wireless communication system,its output power determines the length of the communication distance,its efficiency determines its energy consumption and standby time and so on.So it is always the key direction of RF power amplifier to achieve high linearity while maintaining high efficiency.This paper introduces the structure and performance of various types of RF power amplifier,a comprehensive analysis of the characteristics of various types of amplifier,the gain,output power,efficiency and linearity of the main performance index as the research object of the RF power amplifier.Using discrete components to complete a working frequency of 40MHz’s radio transmitter circuit design.The transmitting circuit mainly comprises an audio amplification circuit,a direct frequency modulation,a buffer,a drive and a power amplifying circuit.The main design parameters of the power amplifier are given.In order to achieve these targets,especially for both the output power and efficiency,the design adopts C power amplifier structure,using load pull method and optimization of source input and output matching network traction,and strive to achieve the actual effect is close to the tuning circuit for use;load to achieve matching amplifier and antenna load.By the design of the circuit for the installation and debugging of the components,work after the actual test,the results show that the transmitting circuit in the input signal for 35~45MHz band power amplifier design is stable,the output power is27 d Bm,the gain is 12.5d B,additional efficiency can reach 41.5% and three order intermodulation distortion is less than-30 d Bc,the indicators meet the design requirements,successfully completed the design task.