Open AccessTime‐division polynomial pre‐distorter for linearisation of 1.5 T MRI power amplifier
Author(s) -
Hui Ming,
Zhang Meng,
Zhang Xingang,
Zhu Xiaowei,
Zhang Xiupu,
Cheng Jiali
Publication year - 2017
Publication title -
the journal of engineering
Language(s) - English
Resource type - Journals
ISSN - 2051-3305
DOI - 10.1049/joe.2017.0195
Subject(s) - amplifier , sinc function , duty cycle , amplitude , modulation (music) , polynomial , signal (programming language) , amplitude modulation , power (physics) , linearity , physics , frequency modulation , control theory (sociology) , mathematics , bandwidth (computing) , computer science , telecommunications , acoustics , optics , mathematical analysis , control (management) , quantum mechanics , artificial intelligence , programming language
A time‐division polynomial (TDP) model is proposed for modelling and linearising a 1.5 T magnetic resonance imaging (MRI) power amplifier (PA) with strong non‐linearity in high input signal dynamic range. In order to demonstrate the merit of this non‐linear model, a 64 dBm 1.5 T MRI PA (63.89 MHz) and two different Sinc‐pulse signals are used in modelling and linearisation measurements. The TDP is compared with the conventional non‐memory polynomial (NMP) and no digital pre‐distortion for the 1.5 T MRI PA, which is driven by test signal with 2 ms time length and 2% duty cycle. The proposed TDP leads to up to 9 dB improvement in the normalised mean square error compared with the NMP in two different test signals. More importantly, TDP illustrates significantly better reduction in amplitude modulation/amplitude modulation (AM/AM) and amplitude modulation/phase modulation (AM/PM) conversion compared with the NMP.