Analysis and design of a wideband high efficiency CMOS outphasing amplifier

• Published in: 2010 IEEE Radio Frequency Integrated Circuits Symposium pp. 399 - 402
• Main Authors: van Schie, M C A, van der Heijden, M P, Acar, M, de Graauw, A J M, de Vreede, L C N
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01-05-2010
• Subjects: Admittance; Amplitude modulation; Bandwidth; Broadband amplifiers; Chireix; CMOS; LINC; Linearity; Outphasing; Phase modulation; Power amplifiers; power combiner; Power combiners; Power generation; transformer; Transmitters
• ISBN: 9781424462407; 1424462401
• ISSN: 1529-2517; 2375-0995
• DOI: 10.1109/RFIC.2010.5477315

This work presents the analysis and design of a novel transformer-based power combining network for an efficient outphasing power amplifier (PA). The proposed power combining network was implemented on PCB together with two 65nm CMOS class-E PA's. Measurements show a peak output power of more than 30dBm over a 29% bandwidth around 700MHz. The peak output power at 700MHz equals 33.9dBm. The 10dB back-off efficiency is larger than 27.3% over the same 29% bandwidth. The 6dB back-off efficiency is larger than 46.4% over this bandwidth. The drain efficiency at 650MHz is larger than 50% over a 10dB power back-off range, which is, to our best knowledge, the highest back-off efficiency reported in a CMOS outphasing PA to date.