Design and performance of a digital polar transmitter system for multiband-OFDM Ultra-WideBand

Abstract

A low-voltage 3-bit Digital Polar Amplifier for MB-OFDM UWB is proposed, which comprises 7 parallel RF amplifiers driven by a constant RF phase-modulated signal and 7 cascode transistors (connected in series) digitally controlled by a 3-bit digitized amplitude signal to reconstruct the UWB signal at the output. Our DPA was able to achieve an EVM of -22 dB and drain efficiency of 21.0% while delivering 5.5 dBm of output power and consuming 17 mW of power using IBM 130-nm CMOS technology.