Title :
A Doherty amplifier with maximally flat efficiency in the bandwidth
Author :
Giofre, R. ; Piazzon, L. ; Colantonio, P. ; Giannini, F.
Author_Institution :
E.E. Dept., Univ. of Roma Tor Vergata, Rome, Italy
Abstract :
This contribution presents a creative circuit level solution to improve the efficiency versus frequency response of the Doherty amplifier. The proposed approach is compared with the conventional one and experimentally validated through a practical prototype realization based on GaN-HEMTs. Continuous wave measurements have shown a 65%-51% efficiency at about 42-36.5-dBm output power from 1.95-GHz to 2.25-GHz. When tested with a mobile WiMAX signal with 5MHz bandwidth and 9.3-dB Peak-to-Average Power Ratio (PAPR), the Doherty amplifier achieved an average efficiency around 50% with an Adjacent Channel Power Ratio (ACPR) lower than -38-dBc. Similar performances have been registered using a signal with 48-MHz bandwidth and 10.3-dB PAPR.
Keywords :
III-V semiconductors; frequency response; gallium compounds; power amplifiers; wide band gap semiconductors; ACPR; Doherty amplifier; GaN; HEMT; PAPR; adjacent channel power ratio; bandwidth 48 MHz; bandwidth 5 MHz; circuit level solution; continuous wave measurements; frequency response; mobile WiMAX signal; peak-to-average power ratio; Bandwidth; Frequency response; Peak to average power ratio; Power amplifiers; Power generation; Prototypes; Wireless communication; Doherty Amplifier; GaN; output combiner;
Conference_Titel :
Microwave Symposium Digest (IMS), 2013 IEEE MTT-S International
Conference_Location :
Seattle, WA
Print_ISBN :
978-1-4673-6177-4
DOI :
10.1109/MWSYM.2013.6697335
