Development Of A High Performance L-Band RF Power Amplifier

With the development of RF and microwave technology,microwave circuit design requirements continue to improve,the power amplifier as a microwave circuit in the core device,its performance directly determines the performance of the entire system.Power amplifier design is difficult to achieve high-power output,high linearity and high efficiency.RF power amplifier in the modern communication system is the main role in the specified frequency band to efficiently amplify the RF small signal,and then through the feeder system to transmit the antenna.The power amplifier consumes the vast majority of the energy in the communication system transmitter,so improving the power amplifier efficiency and output power is an important research area in the field of RF circuit design.At present,phased array radar is widely used in aerospace,electronic warfare,monitoring and control areas,its excellent performance has been unanimously approved.Power amplifier as a phased array radar transmitter components of the core components,a direct impact on the performance of the entire system.In addition,the microwave power amplifier is also a modern wireless communication system is a very important unit,in satellite communications,radio and television,microwave remote sensing and other fields play a pivotal role.Therefore,the study of microwave power amplifier has important application value.This thesis introduces a method for developing L-band power amplifiers for phased array radar transmitters.The main indicators are: 1.35GHz-1.4GHz operating frequency band,1dB compression output power greater than 50 dBm,gain greater than 55 dB,and AC efficiency greater than 45%.The Development of the use of four-stage amplification structure,the final amplification tube selection NXP's LDMOS tube,in order to take into account the efficiency and linearity,the final amplification circuit work in the AB class.This thesis analyzes the structure principle of different circuit functional unit circuits in detail,including bias circuit and matching network.In addition,the current popular and mature amplifier design techniques,including load traction technology,linearization technology and efficiency enhancement technology,are described in detail Research.On this basis,the subject index and related technology were discussed in depth,the overall project indicators were put forward,the design of the sub-circuit and the overall circuit structure,and in accordance with the circuit schematic diagram,designed the PCB map,after debugging,The design of the overall circuit performance indicators reached a pre-proposed requirements..