Title :
A digital Doherty transmitter suitable for wireless infrastructure efficiency enhancement
Author :
Darraji, Ramzi ; Ghannouchi, Fadhel M.
Author_Institution :
Dept. of Electr. & Comput. Eng., Univ. of Calgary, Calgary, AB, Canada
Abstract :
The present work proposes a digital Doherty power amplifier (PA) with improved efficiency performance. The efficiency enhancement is achieved by using a digital adaptive phase alignment mechanism that is implemented to address the problem of power-dependent phase imbalance between the carrier and peaking cells of gallium-nitride (GaN) Doherty PAs following the turn-on of the peaking cell. An average efficiency of 57% has been measured using a one-carrier Worldwide Interoperability for Microwave Access (WiMAX) signal with a peak-to-average power ratio of 7 dB. This corresponds to an improvement of 7% in average efficiency with no linearity degradation compared to a conventional single-input fully analog Doherty PA.
Keywords :
WiMax; power amplifiers; GaN; WiMAX signal; carrier cells; digital Doherty power amplifier; digital Doherty transmitter; digital adaptive phase alignment mechanism; linearity degradation; microwave access; one-carrier worldwide interoperability; peaking cells; power-dependent phase imbalance; single-input fully analog Doherty PA; wireless infrastructure efficiency enhancement; Computer architecture; Degradation; Gallium nitride; HEMTs; Power amplifiers; Power generation; Wireless communication; Doherty power amplifier; GaN; digital signal processing; dual-input architecture; power efficiency;
Conference_Titel :
Mediterranean Microwave Symposium (MMS), 2011 11th
Conference_Location :
Hammamet
Print_ISBN :
978-1-4577-1814-4
Electronic_ISBN :
2157-9822
DOI :
10.1109/MMS.2011.6068550
