A 2.45GHz SiGe Power Amplifier with a Novel Digital Predistortion using Orthogonal Sequences

With the need of maximizing the efficiency of Radio Frequency (RF) systems while respecting strict constraints in terms of EVM requirements, Power Amplifiers (PAs) predistortion appears as a way to improve circuits performances. Indeed, maximum efficiency is near the maximum output power that the PA can display. However, in this use area, PAs introduce distortion and phase variation. In this paper, a novel method for the linearization of RF Power Amplifiers is presented. The sequential transform is first used to evaluate a digital model of predistortion for the PA. A AB-Class PA is designed and is used in the proposed predistortion system to highlight the benefits of the overall architecture.