This paper presents a fully integrated 60 GHz power amplifier in 40nm CMOS that reaches the highest reported product of power-added efficiency and bandwidth. It is achieved through low/moderate coupling-factor transformers in the preliminary stages and a proper second harmonic termination of the output stage, such that it can operate as a class-E/F2 switched-mode PA at the saturation point. The three-stage PA delivers 17.9dBm saturated output power with 20% peak PAE. It demonstrates a bandwidth of 9.7 GHz with a peak gain of 21.6 dB.