FPGA-based digital predistortion of A 3.5 GHz GaN Doherty power amplifier

Author

Jiang, T. ; Quaglia, R. ; Camarchia, V. ; Pirola, M.

Author_Institution

Dept. of Electron. & Telecommun., Politec. di Torino, Turin, Italy

fYear

2014

Firstpage

20

Lastpage

24

Abstract

In this paper, a baseband predistortion scheme is applied and implemented into real-time FPGA to linearize a Doherty power amplifier for wireless applications. The baseband behavioral models of the Doherty amplifier are based on the Memory Polynomial approach and the direct learning method is applied to estimate the model of the predistorter. For our Doherty power amplifier with a 256QAM I/Q input signal with 7.4 dB Peak to Average Power Ratio at a center frequency of 3.5 GHz, a significant improvement of nearly 10 dB Adjacent Channel Power Ratio reduction has been obtained with a 36.8 dBm average output power and a 45% average efficiency.

Keywords

III-V semiconductors; field programmable gate arrays; gallium compounds; linearisation techniques; microwave amplifiers; power amplifiers; quadrature amplitude modulation; radiocommunication; wide band gap semiconductors; 256 QAM I/Q input signal; Doherty power amplifier; FPGA; GaN; amplifier linearization; baseband predistortion; digital predistortion; direct learning method; frequency 3.5 GHz; memory polynomial; wireless applications; Baseband Predistortion; Doherty Amplifier; FPGA;

fLanguage

English

Publisher

iet

Conference_Titel

Wireless Communications, Networking and Mobile Computing (WiCOM 2014), 10th International Conference on

Print_ISBN

978-1-84919-845-5

Type

conf

DOI

10.1049/ic.2014.0065

Filename

7129593