Microwave Power Amplifier With Adaptive Pre-distortion Linearization Techniques

Power amplifiers are the important part in the wireless telecommunication systems.Because of the unlinearization of the power amplifiers, the relationship between the output signal and the input signal of power amplifiers is not linear. So we need to do something to improve the linearity of the power amplifiers.The main method is predistortion. By monitoring the out-of-band power we can obtain an estimate for the distortion introduced by the power amplifier. Adaptation is accomplished by iterative adjustment of the predistorter parameters to minimize the IM power. For a polynomial predistorter, what we need to do is to determine the coefficients of the polynomial predistorter.The proposed implementation includes hardware and software. For hardware, a platform for predistortion system is accomplished with TMS320VC5509 and EP2C5Q208C7 as the core, which provides the hardware foundation for the whole system.Software implementation is emphasized in this thesis, including(1)adaptive search algorithm;(2)DSP Lib;(3)analyse the results.With the proposed design in this thesis, the linearization of the power amplifier has been improved, and the interference has been reduced.At the end of this thesis, the results are analyzed, problems are pointed out,and the implementation for the future are also dicussed.