The Design Of12M-1GHz Microwave Broadband Power Amplifier

With the development of contemporary wireless communication technology, theuse of broadband power amplifiers in mobile communication system becomes more andmore popular. The broadband power amplifier plays an important role in the structure ofcontemporary communications systems. The requirement we demand for broadbandpower amplifier is growing. We need power amplifier with wider bandwidth, higheroutput power, linearity and efficiency, and better performance of gain flatness in theoperating frequency range.This type of broadband microwave power amplifier is used in the construction ofthe laboratory and the outdoor broadband communications test platform. The operatingfrequency range of this broadband power amplifier is12MHz-1GHz, output power isabout1W, the gain flatness in the operating frequency range needs less than3dB, at thesame time, the power amplifier should have high efficiency.The first chapter introduces the development of broadband power amplifier and thesignificance of this research. The second chapter introduces the classification and basicparameters of broadband power amplifier. The third chapter introduces the influence ofinductance and capacitance of via and pad on PCB.Then we use this theory to revise aLC low-pass filter in the operating frequency range of0-1GHz. The simulation resultwe revised and actual test result matched so well，then we use this theory to revise thebroadband power amplifier. The structure of the broadband amplifier is a two-stagepower amplifier, and we get the parameters of the transistor we use in the amplifierfrom the manufacturers, and we use the ADS simulation software to design thematching network circuit and the gain compensation circuit for the power amplifier.Finally we get a simulation result of the power amplifier. Chapter IV introduces thedesign of the power amplifier schematic and the drawing of PCB. We design theschematics with the reference of ADS software simulation and draw the PCB layoutwith the reference of the schematics. Chapter V is about the debugging of the poweramplifier. Firstly we debug the DC bias of the power amplifier, with mak ing the two transistors of the power amplifier work in the proper working conditions, and then wedebug the matching network circuit and gain compensation circuit to require better gainflatness. Finally we test the power amplifier and draw the input and o utput power curvesand the efficiency curves of the power amplifier.In this thesis, we design a microwave broadband power amplifier. The operatingfrequency range is about12MHz-1GHz, gain flatness is less than3dB, the maximumoutput power is about1W, efficiency is about25%。...