Simulation of Digital Baseband Predistortion System for PA

In order to overcome nonlinear distortion of power amplifier(PA) and meet the requirement of power spectral density mask specified by regulatory bodies,digital baseband predistortion technique is applied because of its advantages such as good linearity,wide bandwidth,high efficiency and full adaptation and it becomes the first choice of overcoming distortion of nonlinear PA.This paper,based on analyzing the principle of digital baseband predistortion system and unit tap delay memory polynomial model,proposes a memory effect digital baseband predistortion system and realizes system-level simulation under ADS circumstance.Simulation results show that this system improves power spectrum density up to 30dBm,and has good predistortion effectiveness.So the created system-level simulation circuit plays an important role in designing practical predistorter.