Digital Predistortion of Single and Concurrent Dual BandRadio Frequency GaN Amplifiers with Strong NonlinearMemory Effects

• Published in: IEEE transactions on microwave theory and techniques Vol. 65; no. 7; p. 2453
• Main Authors: Amin, Shoaib, Händel, Peter, Rönnow, Daniel
• Format: Journal Article
• Language: English
• Published: 2017
• Subjects: Behavioral modeling; concurrent dual band; digital predistortion (DPD); finite impulse response (FIR); infinite impulse response (IIR); power amplifiers (PAs); radio frequency; single-input single-output (SISO)
• ISSN: 0018-9480; 1557-9670
• DOI: 10.1109/TMTT.2016.2642948

Electrical anomalies due to trapping effects in gallium nitride (GaN) power amplifiers (PAs) give rise to long-term or strong memory effects. We propose novel models based on infinite impulse response fixed pole expansion techniques for the behavioral modeling and digital predistortion of single-input single-output (SISO) and concurrent dual-band GaN PAs. Experimental results show that the proposed models outperform the corresponding finite impulse response (FIR) models by up to 17 dB for the same number of model parameters. For the linearization of a SISO GaN PA, the proposed models give adjacent channel power ratios (ACPRs) that are 7-17 dB lower than the FIR models. For the concurrent dual-band case, the proposed models give ACPRs that are 9-14 dB lower than the FIR models.