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Complementary predistorter in CMOS differential power amplifier
Author(s) -
Oh InnYeah,
Ra KeukHwan,
Park ChulSoon
Publication year - 2010
Publication title -
microwave and optical technology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.304
H-Index - 76
eISSN - 1098-2760
pISSN - 0895-2477
DOI - 10.1002/mop.25062
Subject(s) - amplifier , electrical engineering , cmos , operational transconductance amplifier , wimax , electronic engineering , triode , transconductance , linearity , engineering , differential amplifier , physics , transistor , telecommunications , wireless , voltage , capacitor
For adaptive improvement of linearity above a 12 dB PAPR for 64QAM WiMAX, a complementary feedback loop in a differential amplifier is adopted as a pre‐distorter that is realized using an NMOS cell operating in the triode region in order to compensate the g m 3 , the third order transconductance, of the differential amplifier. The power amplifier has been implemented in 0.18 μm CMOS technology, and the chip size is 870 μm × 1050 μm. The proposed PA obtains the 42% efficiency at P1dB while improving the IMD by more than 10 dB above 15 dBm output power levels. It shows a gain of as much as 14.5 dB, and a return loss below −12 dB for 2.3–2.4 GHz operation. Finally, the fabricated PA complies with the spurious emission of WiMAX standards up to 22 dBm. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:833–836, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25062