Study And Application On Analog Predistortion Generator

With the rapid development of communication system, there are more andmore users, and the resource of frequency becomes more and more scarce. To holdmore channels in limited spectrum, the linear modulation techniques of higherspectrum utilization are required. These modulations result in the changes of thesignal envelope. Since the envelope of modulated signal fluctuates, these methodsgenerate unwanted intermodulation distortion (IMD) products in a nonlinear RadioFrequency (RF) Power Amplifier (PA). And on the other hand, the moderncommunication system requires the higher linearity of the power amplifier that islimited itself. So it is necessary to use linearization techniques to improve thelinearity of the power amplifier and to reduce the IMD.In this dissertation, Firstly, the characteristics of RF power amplifiers areintroduced. And then, a few linearization techniques are presented. We choose themethod of predistortion and design two new predistortion generators. They aremodulated type predistortion generator and self-cancellation predistortion generator.Then the work principle is analyzed. The main points of RF power amplifier designare presented during the design of MRF21030. In order to prove the results, thepredistortion generators are implemented to the RF PA. Finally, a new temperaturecompensation system is introduced. This temperature compensation is a good methodfor the linearization system and easy to set up.