The Analysis And Design Of Adaptive Control Detection Of RF Feedforward PA

As the business implementation of the third generation mobile communication system,the requirement of the terminal equipment have been increased a lot. Because of high spectral efficiency and speed in these system,high linearity of RF amplifier is required necessarily. Feedforward technology is a good method implicated in power linearity,therefore,the research of RF feedforward power amplifier is a practical and challenge topic.Firstly, the nonlinearity of RF power amplifier has been analyzed in this thesis, according to the changeable envelope modulation technology and multi-carrier transmittance method adopted in the modern communication system widely, the nonlinearity of PA have been discussed by these two method importantly. Secondly, the relevant indicators of PA have been introduced specifically, such as the definition of linearity degree, intermedium interference degree and so on. In the status of large signal and multi-carrier modulation, the nonlinear distortion exist in all common amplifier,it is critical and necessary to design high linearity degree amplifier for the modern communication system. There have some ways to improve the amplifier's linearity including feedforward, power backward and pre-distortion. The advantage of feedforward method has been emphasized according to the comparison among these methods.The feedforward method has been discussed in detail combined with the modern communication system application including principle, mathematic model and software simulation. The one importance of the thesis is to analysis and design the adaptive control detection. One new detection method of inserted lead frequency modulated quarter audio signal has been analyzed as the one creation point of this thesis. Not only the principle, mathematic analysis and ADS software simulation have been discussed, but the hardware design has been analyzed and realized in detail. Another part of my thesis is adaptive control; a mathematic method LMS has been discussed, the hardware also has been designed in detail.