Radio frequency power amplifiers (PAs) play a key- role in transceivers for mobile communications and their linearity is a crucial aspect. In order to meet the linearity requirements dictated by the standard at a reasonable efficiency, the usage of a linearization technique is required. In this paper we propose a linearization by means of a new type of digital predistorter, defined directly in the I-Q domain. The architecture of the proposed predistorter can be understood as an enhancement of the memory polynomial model (MPM) by means of additional I-Q terms. The usage of the proposed predistorter allows a more robust linearization of the whole RF transmitter because the enhancement of the model with additional I-Q terms can guarantee a more versatile compensation which is beneficial when the distortion comes from the joint contribution of the PA and the quadrature modulator. The proof of concept is achieved by measurements on a commercial PA in GaN technology and the performance of the proposed predistorter is illustrated.
|Autori interni:||GUARAGNELLA, Cataldo|
|Titolo:||Linearization of RF Power Amplifiers Using an Enhanced Memory Polynomial Predistorter|
|Data di pubblicazione:||2012|
|Nome del convegno:||NORCHIP 2012|
|Digital Object Identifier (DOI):||10.1109/NORCHP.2012.6403124|
|Appare nelle tipologie:||4.1 Contributo in Atti di convegno|