Abstract: Bandwidth of the feedback signal from the output of the power amplifier is too wide，and it needs high sampling rate to sample the feedback signal.For this problem，this paper proposes a predistortion linearization technology based on the under-sampling method，allowing the system to sample the feedback signal at a lower sampling rate，which is no smaller than two times of the input signal’s bandwidth.It has no affect to the identification of the power amplifier’s nonlinearity，and can achieve the same linear performance compared with the over-sampling method.So the predistortion linearization system is easier to design and realize.Simulation results show the correctness and the satisfactory linearization performance of this method，the conclusion is significance to the engineering practical application.

Key words: power amplifier, under-sampling, nonlinearity, predistortion, adaptive

摘要： 针对经功放输出后反馈回的信号频谱带宽较宽，对采样率要求较高的问题，提出一种基于欠采样方法的预失真线性化技术，使系统最低能以两倍输入信号带宽的采样率采样反馈信号，但却不影响对功放非线性参数的识别，且能达到与过采样方式相同的线性化性能，降低了数字基带预失真系统设计和实现的难度。仿真结果表明该方法是可行的，且能达到满意的线性化效果，该结论在工程实际应用中具有重要意义。

关键词: 功率放大器, 欠采样, 非线性, 预失真, 自适应