EXTENDED BANDWIDTH DIGITAL DOHERTY TRANSMITTER

摘要

An extended bandwidth digital Doherty transmitter includes a baseband signal processing block including a digital predistortion unit. It also includes a digital signal distribution unit and a digital phase alignment unit, a signal up-conversion block, an RF power amplification block including the carrier amplifier and one or two peaking amplifiers; and an RF Doherty combining network. In another aspect, a digital Doherty transmitter includes a baseband signal block including a digital predistortion unit, a digital signal distribution unit and an adaptive digital phase alignment unit. In this aspect a signal up-conversion block includes three digital-to-analog converters (DACs) and a tri-channel up-converter or three single-channel up-converters. There is also an RF power amplification block including the carrier amplifier and two peaking amplifiers, and an RF Doherty combining network which includes quarter wavelength impedance transformers.