A 3.3 V single voltage se[S-biased 2.4GHz-2.5GHz high linearity AlGaAs/InGaAs/GaAs PHEMT MMIC power amplifier for wireless local-area network (WLANk) applications (Dual channel for 802.IIdb combination systems) is demonstrated. This two-stage amplifer is designed to fully match for a 50 ohm input and output impedance. In this process, a backside via-ground methodi s not used, so it can offer very low cost for the production of wireless LAN IC. Mth only a 3.3V drain voltage, the ampliJier has achieved 30dB small-signal gain, 23.5dBm I-dB gain compression power with 24.2% power-added eflciency (PAE). In addition. high linearity with 37. 2dBm third-order intercept point at frequency of Z.45GHz is achieved. For this power amplifier MMIC, the WLAN requirements of power amplifiers including aspects of high efjciency, high gain, high linearity and operation at 2.4GHz ISM band are procured.