Multitone Digital Predistortion Method of RF Power Amplifiers for 5G Systems

Abstract

An effective method to enhance Adjacent Channel Leakage Ratio (ACLR) and Error Vector Magnitude (EVM) in the presence of multitone amplitude and phase variation within the carrier band and adjacent frequencies for power amplifiers using predistortion is developed and demonstrated for 5G Systems. The effects of multiple tones with varying amplitude and phase are studied and the closed form relations for predistortion coefficients are obtained for cancellation of the intermodulation products. The proposed method was then verified through physical measurements using a commercial power amplifier where reduction of intermodulation was achieved, and the adjacent leakage ratio performance was improved.