High Efficiency RF Power Amplifier Designed With Harmonic Real-Time Active Load-Pull

• Published in: IEEE microwave and wireless components letters Vol. 18; no. 4; pp. 266 - 268
• Main Authors: Xian Cui, Seok Joo Doo, Roblin, P., Strahler, J., Rojas-Teran, R.G.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.04.2008; Institute of Electrical and Electronics Engineers
• Subjects: Amplifiers; Applied sciences; Circuit properties; Compressing; Electric, optical and optoelectronic circuits; Electronic circuits; Electronic equipment and fabrication. Passive components, printed wiring boards, connectics; Electronics; Exact sciences and technology; Harmonics; High power amplifiers; Large signal network analyzer (LSNA); Microwave circuits, microwave integrated circuits, microwave transmission lines, submillimeter wave circuits; Microwaves; Network synthesis; Noise levels; Optimization; power added efficiency (PAE); power amplifier (PA); Power amplifiers; Power generation; Power system harmonics; Radio frequencies; Radio frequency; Radiofrequency amplifiers; Real time; real-time active load-pull (RT-ALP); RF signals; Signal analysis; Signal design; Network analyzer; Performance evaluation; Harmonic; Large signal network analyzer (LSNA); Microwave power amplifiers; Output power; power amplifier (PA); Large signal behavior; Power electronics; Mismatching; Implementation; High electron mobility transistor; power added efficiency (PAE); Radiofrequency amplifiers; Pseudomorphic transistor; Power amplifier; Impedance; real-time active load-pull (RT-ALP)
• ISSN: 1531-1309; 1558-1764
• DOI: 10.1109/LMWC.2008.918913

In this work, a high efficiency p-HEMT radio frequency power amplifier (PA) is designed using a new multiharmonic real-time active load-pull using the large signal network analyzer. This technique synthesizes a large set of instantaneous load mismatches to quickly find the optimal harmonic impedances, so as to achieve high PA efficiency in a shortened design cycle. At 2 GHz a demo power amplifier implemented with a p-HEMT demonstrated a power added efficiency (PAE) of 68.5% for 18.0 dBm output power, while achieving a maximum PAE of 75% below the 1 dB compression point for 18.6 dBm output power.