A fully integrated CMOS power amplifier with a half-turn transformer for IEEE 802.11a WLAN applications

A fully integrated CMOS power amplifier for 5 GHz WLAN applications is implemented using 0.18 μm CMOS technology. An on-chip transmission-line transformer is used for output matching and voltage combining. An input balun, interstage matching components, an output transmission-line transformer, and RF chokes are fully integrated in the amplifier, and thus no external components are required. The power amplifier occupies a total area of 1.7 mm × 1.2 mm. At a 3.3 V supply voltage, the amplifier exhibits a 22.6 dBm output 1 dB compression point, 23.8 dBm saturated output power, and 25 dB power gain. The power added efficiency (PAE) is 21% at maximum, 19% at P1dB. When a 54 Mbps/64 QAM OFDM signal is applied, the PA delivers an average power of 12 dBm at an EVM of −25 dB. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2551–2553, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24683