Design Of RF Power Amplifier

With the development of RF and micorwave technology, the requirements ofmicrowave circuit keep getting higher and higher. Power ampilifier(PA) is one of themost important components in microwave circuit, which directly influences thewhole system’s performance.The difficulty of designing PA is to realize high poweroutput, high linearity and high effciency. Wireless communication system requiresPA to be of good lineraity, while handheld device needs good effciency. thebroadening of working communication bandwidth requires PA to be able to work ina ultra wide band.In this paper, working principle and application of PA is analysied.Semiconductor pomponents which decide the PA’s performance is presented,including the LDMOS structure. The details of different function circuit units, suchbias network and match network circuits is introduced. This paper also discussed thestate-of-art PA design technology, including load-pull, linearization, and effciencyenhancement. Based on the analysis of design target, details of the design processfrom general targets, function units design and realization is presented. With thehelp of ADS software, the design results satisfy the requirements.The main work of this article includes:According to the general design target, the circuit structure is designed andanalysised.The first stage ampilifer circuit focuses on high gain and high linearity; thesecond stage is designed to provide enough driving power; and the last stage circuitstresses in high power output and high effciency. Components are choosed for eachcircuit.Based on the analysis of PIN diode, voltage-control attenuator is design tosatisfy different input singal requirement.The details of the last stage circuit is presented, including bias and sourcefilting circuit, matching circuit, etc.The circuit is optimized by schematic-layout co-simulation.