A 5.25-GHz CMOS cascode class-AB power amplifier for 802.11a WLAN

In this paper, we investigate a 5.25-GHz highly integrated CMOS class-AB power amplifier for IEEE 802.11a WLAN. The proposed power amplifier is implemented with a two gain-stage structure which is followed by an off-chip output matching circuit. Moreover, a transistor-level compensation technique is employed to improve the linearity. The measured results indicate an over 20% power-added efficiency, an over 20 dBm output power, and an 18.8-dBm output 1-dB compression point. All the specifications are based on 50-Omega input impedance at 2.4 V supply voltage.