A 5.3-GHz 30.1-dBm Fully Integrated CMOS Power Amplifier With High-Power Built-In Linearizer

— A 5.3-GHz watt-level fully integrated CMOS power amplifier (PA) with a high-power built-in linearizer is presented in this letter. Utilizing a transformer (TF)-based 2-stage dual-radial power splitting/combining structure, the CMOS PA achieves watt-level output power. To enhance the linearity of the CMOS PA, a cascode cold-FET built-in linearizer which has high power capacity is developed. The CMOS PA achieves 30.1-dBm saturation output power (P_sat ), 27 dBm output 1-dB compression point (OP_1dB ), 27.7 dB small signal gain, and 18% power added efficiency (PAE) at 5.3 GHz after linearization. Under the IEEE 802.11ac WLAN 20/80 MHz bandwidth 64/256 QAM OFDM modulated signals, the CMOS PA transmits linear output power (P_linear ) of 21/17 dBm with 5.6%/2.5% error vector magnitude (EVM), respectively. To our knowledge, the CMOS PA demonstrates the highest P_linear and OP_1dB among other reported CMOS PAs around 5 GHz to date.