Analog and Digital Wideband Envelope Tracking for 5G

The demand for high data rates and better throughput has driven 5G communication systems to use higher order modulations. To overcome the efficiency degradation in power amplifiers in the presence of such waveforms, advance power amplifier architectures are needed. Among them is the envelope tracking power amplifier (ETPAs). In this talk, ETPAs based on both analog and digital modulators will be described and compared. Analog modulators, with hybrid architectures of different switching and linear stages in parallel and series configurations, and digital modulators, producing envelope approximates use as power DACs, multi-switchers, or tap-changers, are compared in terms of their performance merits (waveform fidelity, bandwidth, efficiency, etc), with emphasis on 5G applications. ETPAs designs and considerations for enabling digital communication systems with multi beam/multi-channel transmission will be discussed. Linearization techniques for both analog and digital ETPAs and multi-beam/multi-channel operation will be shown.