A 5.8 GHz 1 V linear power amplifier using a novel on-chip transformer power combiner in standard 90 nm CMOS

A fully integrated 5.8 GHz Class AB linear power amplifier (PA) in a standard 90 nm CMOS process using thin oxide transistors utilizes a novel on-chip transformer power combining network. The transformer combines the power of four push-pull stages with low insertion loss over the bandwidth of interest and is compatible with standard CMOS process without any additional analog or RF enhancements. With a 1 V power supply, the PA achieves 24.3 dBm maximum output power at a peak drain efficiency of 27% and 20.5 dBm output power at the 1 dB compression point.