基于数/模混合预失真技术的功放线性化北大核心CSCD

随着移动通信信号带宽的增加,传统功率放大器数字预失真线性化技术越来越受到采样率的限制。为了使线性化效果更好,文中提出了一种数字预失真和模拟预失真相结合的混合预失真器,利用模拟预失真宽带宽的特点和数字预失真线性化能力强的优势,把模拟预失真和数字预失真融合在一起,共同补偿功放的非线性。由于受实验设备采样率的限制,文中采用了带宽为60 MHz的5 G NR信号对一个中心频率为3.5 GHz的射频功放进行实验验证。实验结果表明:提出的混合预失真器不仅优于单独的数字预失真器和模拟预失真器的非线性矫正性能,而且还能改善数字预失真因采样率限制无法改善的带外互调失真。

Linearization of Power Amplifier Based on Digital / Analog Hybrid Predistortion Technology

With the increase of the mobile communication signal bandwidth, the traditional digital predistortion (DPD) linearization technology for the power amplifier (PA) is more and more limited by the sampling rate. In order to make the linearization effect better, a hybrid predistorter combining the DPD and the analog predistortion (APD) is proposed in this paper. Using the advantages of the wide-bandwidth of the APD and the high linearization ability of the DPD, the APD and DPD are combined to compensate the nonlinearity of the PA. Due to the limitation of sampling rate of the experimental equipment, a 5 G NR signal with 60 MHz bandwidth is used to verify an RF PA with 3. 5 GHz center frequency. The experimental results show that the proposed hybrid predistorter not only has better nonlinear correction performance than single digital predistorter and analog predistorter, but also can improve the out-of-band intermodulation distortion which could not be improved due to the limitation of sampling rate.