A Millimeter-Wave Dual-Band Class-F Power Amplifier in 90 nm CMOS

A 28/38 GHz dual-band class-F power amplifier (PA) using 90-nm CMOS process is proposed. The efficiency of the two-stage PA is enhanced by the proposed dual-band class-F output matching network, in which the harmonic impedance of both bands is controlled to fulfill the voltage and current waveform for class-F operation. The proposed PA achieves a measured small-signal gain of 20.5 and 14.6 dB, saturation output power (P sat ) of 15.5 and 13.1 dBm, peak power-added efficiency (PAE) of 27.2 and 16.4%, output 1-dB compression power (OP 1dB ) of 13.9 and 11.4 dBm at 28 and 38 GHz, respectively.