An efficient, linear, broadband class-J-mode PA realised using RF waveform engineering

• Published in: 2009 IEEE MTT-S International Microwave Symposium Digest pp. 653 - 656
• Main Authors: Wright, P., Lees, J., Tasker, P.J., Benedikt, J., Cripps, S.C.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.06.2009
• Subjects: Bandwidth; Broadband amplifiers; class-J; Gallium nitride; HEMTs; high efficiency; High power amplifiers; III-V semiconductor materials; power amplifiers; Power engineering and energy; Power measurement; Radio frequency; Radiofrequency amplifiers
• ISBN: 1424428033; 9781424428038
• ISSN: 0149-645X
• DOI: 10.1109/MWSYM.2009.5165781

Results from a fully implemented class-J RFPA (RF power amplifier) are presented for the first time, which demonstrate this mode's high efficiency potential across a substantial bandwidth. Using a commercially available 10W GaN (gallium nitride) HEMT device, and the high power waveform measurement and active load-pull capability at Cardiff University, class-J operation has demonstrated drain efficiencies between 60-70% across a 1.35-2.25 GHz (50%) bandwidth whilst delivering 10 Watts of power at the 2dB compression point. Realisation of the design has confirmed that the optimum harmonic load impedances of the class-J amplifier are more practically realisable than conventional class-AB modes, with better compromise between power and efficiency tradeoffs over a substantial RF bandwidth.