Multilevel LINC System Design for Wireless Transmitters

Linear amplifier with nonlinear components (LINC) is a power linearization method which offers both high linearity and high power amplifier (PA) efficiency in wireless transmitters. While LINC increases the power efficiency of PAs, this linearization technique requires an extra power combiner which results in low power efficiency of whole system. To improve this drawback, we propose a multi-level LINC (ML-LINC) method to not only increase power combiner efficiency but also maintain high linearity of wireless transmitters. We also derive the optimal value of each scaling level to maximize the power combiner efficiency. Finally, we demonstrate a four-level scaling ML-LINC as a design example which enhances power combiner efficiency from 44.5% to 80.8% and maintains high linearity to fulfill WCDMA specifications.