Ads-based Design And Simulation Of RF Power Amplifiers

In recent years with the rapid development of wireless communication, the modern communication system is getting higher and higher to transmitter's request, the radio frequency power amplifier takes transmitter's important part, is playing the key role to the transmitter system's performance index, the power amplifier in the entire wireless communication system is a very important part, because its output has decided the length of communication distance, its efficiency has decided battery's consumption degree and use of time, therefore the design performance target good radio frequency power amplifier has the very vital significance.This article carries on the modelling simulation with the aid of the ADS simulation software's powerful function to the transistor, has carried on the analysis in this foundation to transistor's stability, has used the method of load-pull and the Smith circle diagram, to input the output impedance match circuit to carry on the simulation optimization design.The main work of this paper is as follows:1.The paper analysises the RF power amplifiers causes of nonlinear characteristics and their effect on communication systems from a power amplifier of the physical structure, discusses the power amplifier of nonlinear analysis model, that is, power series, Volterra series and harmonic balance analysis model, and a brief description of their respective characteristics, summarizes the advantages of harmonic balance analysis, that it is suitable for RF power amplifier large signal nonlinear analysis.2.The paper analysises the radio frequency power amplifier bias and in match circuit design some basic questions, compares with the advantages and disadvantages of active and passive bias network, discusses the input and output matching circuit and interstage matching circuits of the key issues . Introduces the method of load-pull design, that are equipped with power tube large signal model to load and source for pulling simulation ,thus determines the output and input impedance.3.In the RF power amplifier design process, the main use of the ADS software to aid analysis and design. It is through the full application of the software functions, replacing many of the original RF amplifier design requires manual operations carried out design work, improves work efficiency. From the simulation results are expected design goals, verify that shows ADS simulation software in RF circuit design practicability and superiority, has to continue the in-depth study of the value.