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Augmented twin-nonlinear two-box behavioral models for multicarrier LTE power amplifiers.

Hammi O - ScientificWorldJournal (2014)

Bottom Line: A novel class of behavioral models is proposed for LTE-driven Doherty power amplifiers with strong memory effects.When strong memory effects are observed, the augmented twin-nonlinear two-box models can improve the normalized mean square error by up to 3 dB for the same number of coefficients when compared to state-of-the-art twin-nonlinear two-box models.Furthermore, the augmented twin-nonlinear two-box models lead to the same performance as previously reported twin-nonlinear two-box models while requiring up to 80% less coefficients.

View Article: PubMed Central - PubMed

Affiliation: Electrical Engineering Department, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia.

ABSTRACT
A novel class of behavioral models is proposed for LTE-driven Doherty power amplifiers with strong memory effects. The proposed models, labeled augmented twin-nonlinear two-box models, are built by cascading a highly nonlinear memoryless function with a mildly nonlinear memory polynomial with cross terms. Experimental validation on gallium nitride based Doherty power amplifiers illustrates the accuracy enhancement and complexity reduction achieved by the proposed models. When strong memory effects are observed, the augmented twin-nonlinear two-box models can improve the normalized mean square error by up to 3 dB for the same number of coefficients when compared to state-of-the-art twin-nonlinear two-box models. Furthermore, the augmented twin-nonlinear two-box models lead to the same performance as previously reported twin-nonlinear two-box models while requiring up to 80% less coefficients.

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Related in: MedlinePlus

Measured AM/AM and AM/PM characteristic of the 2140 MHz Doherty PA driven by the 4-carrier LTE signal. (a) AM/AM characteristic and (b) AM/PM characteristic.
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fig4: Measured AM/AM and AM/PM characteristic of the 2140 MHz Doherty PA driven by the 4-carrier LTE signal. (a) AM/AM characteristic and (b) AM/PM characteristic.

Mentions: First, the Doherty amplifiers were characterized by acquiring their input and output baseband complex waveforms. The technique thoroughly described in [1] consists in using the baseband complex waveform measured at the output of the DUT with a vector signal analyzer along with its counterpart at the input of the DUT. The measurements were processed to time align the measured waveforms and then derive the AM/AM and AM/PM characteristics of each amplifier. These characteristics are reported in Figures 3 and 4 for the 2425 MHz Doherty amplifier and the 2140 MHz Doherty amplifier, respectively.


Augmented twin-nonlinear two-box behavioral models for multicarrier LTE power amplifiers.

Hammi O - ScientificWorldJournal (2014)

Measured AM/AM and AM/PM characteristic of the 2140 MHz Doherty PA driven by the 4-carrier LTE signal. (a) AM/AM characteristic and (b) AM/PM characteristic.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3927868&req=5

fig4: Measured AM/AM and AM/PM characteristic of the 2140 MHz Doherty PA driven by the 4-carrier LTE signal. (a) AM/AM characteristic and (b) AM/PM characteristic.
Mentions: First, the Doherty amplifiers were characterized by acquiring their input and output baseband complex waveforms. The technique thoroughly described in [1] consists in using the baseband complex waveform measured at the output of the DUT with a vector signal analyzer along with its counterpart at the input of the DUT. The measurements were processed to time align the measured waveforms and then derive the AM/AM and AM/PM characteristics of each amplifier. These characteristics are reported in Figures 3 and 4 for the 2425 MHz Doherty amplifier and the 2140 MHz Doherty amplifier, respectively.

Bottom Line: A novel class of behavioral models is proposed for LTE-driven Doherty power amplifiers with strong memory effects.When strong memory effects are observed, the augmented twin-nonlinear two-box models can improve the normalized mean square error by up to 3 dB for the same number of coefficients when compared to state-of-the-art twin-nonlinear two-box models.Furthermore, the augmented twin-nonlinear two-box models lead to the same performance as previously reported twin-nonlinear two-box models while requiring up to 80% less coefficients.

View Article: PubMed Central - PubMed

Affiliation: Electrical Engineering Department, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia.

ABSTRACT
A novel class of behavioral models is proposed for LTE-driven Doherty power amplifiers with strong memory effects. The proposed models, labeled augmented twin-nonlinear two-box models, are built by cascading a highly nonlinear memoryless function with a mildly nonlinear memory polynomial with cross terms. Experimental validation on gallium nitride based Doherty power amplifiers illustrates the accuracy enhancement and complexity reduction achieved by the proposed models. When strong memory effects are observed, the augmented twin-nonlinear two-box models can improve the normalized mean square error by up to 3 dB for the same number of coefficients when compared to state-of-the-art twin-nonlinear two-box models. Furthermore, the augmented twin-nonlinear two-box models lead to the same performance as previously reported twin-nonlinear two-box models while requiring up to 80% less coefficients.

Show MeSH
Related in: MedlinePlus