A fully integrated 2.4GHz adaptive biased CMOS power amplifier for 802.11g WLAN application

A 2.4GHz fully integrated CMOS power amplifier with adaptive bias is presented in this paper. The output stage of the proposed power amplifier is adaptively biased by using a novel feed forward control circuit. The bias current is automatically adjusted according to the input power level. The efficiency is improved at the 6 dB power back off (PBO) point. The proposed power amplifier is fabricated in 0.18um CMOS process. The 1-dB compression output power is 22.5dBm with 30.4% power added efficiency (PAE), while the output power and PAE at 6 dB back off point for 802.11g WLAN application is 16.9 dBm and 12.9%.