Abstract

A new predistortion scheme based on active devices is presented in this paper.Through a simplified theoretical analysis a preliminary dimensioning of the structure is first performed;then a circuit optimization, based on very accurate modeling of the various active and passive blocks,allows obtaining a significant reduction of intermodulation distortion (IM3)of the PA to be linearized. The proposed predistortion architecture has been verified using Agilent ADS simulator for accomplishing two-tone and 16QAM analyses,firstly by means of behavioral components;then a CAD implementation based on TriQuint Semiconductors library for GaAs MMIC process has been simulated,confirming the expected performances.Also a worst-case analysis has been performed,demonstrating the robustness of the proposed solution.