Evaluation of a GaN HEMT transistor for load- and supply-modulation applications using intrinsic waveform measurements
Paper in proceeding, 2010
In this paper, the efficiency of a GaN HEMT transistor and its intrinsic waveforms are measured at 0.9 GHz and investigated for load- and supply-modulation applications. The results show that both techniques perform equally well for back-off levels ≤6.5 dB. At higher back-off levels, the efficiency improvements achieved by supply modulation outperform load modulation. At 10 dB back-off, supply, and load modulation provide a power-added efficiency (PAE) of 68%, and 58%, respectively. Using measured intrinsic waveforms, it is shown that PAE degradations in load modulation can be mainly attributed to parallel losses rather than series losses, which are dominant in supply modulation. The harmonic contents of the intrinsic waveforms, in both techniques, are equally strong in back-off and peak power operations. There is, therefore, a great potential for further efficiency enhancement by circuit-level optimization of harmonic terminations for back-off. © 2010 IEEE.
Load modulation
Efficiency
Supply modulation
Power amplifier
GaN HEMT
Author
Hossein Mashad Nemati
GigaHertz Centre
Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics
Alan L. Clarke
Cardiff University
Steve C. Cripps
Cardiff University
Johannes Benedikt.
Cardiff University
Paul J. Tasker
Cardiff University
Christian Fager
Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics
GigaHertz Centre
Jan Grahn
GigaHertz Centre
Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics
Herbert Zirath
GigaHertz Centre
Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics
IEEE MTT-S International Microwave Symposium Digest
0149645X (ISSN)
509-512 5517696978-142447732-6 (ISBN)
Subject Categories (SSIF 2011)
Electrical Engineering, Electronic Engineering, Information Engineering
DOI
10.1109/MWSYM.2010.5517696
ISBN
978-142447732-6