A 50 to 70 GHz wideband power amplifier (PA) is developed in MS/RF 90 nm 1P9M CMOS process. This PA achieves a measured sat of 13.8 dBm, 1 dB of 10.3 dBm, power added efficiency (PAE) of 12.6%, and linear power gain of 30 dB at 60 GHz under DD biased at 1.8 V. When DD is biased at 3 V, it exhibits sat of 18 dBm, 1 dB of 12 dBm, PAE of 15%, and linear gain of 32.4 dB at 60 GHz. The MMIC PA also has a wide 3 dB bandwidth from 50 to 70 GHz, with a chip size of 0 66 0 5 mm 2 . To the author's knowledge, this PA demonstrates the highest output power, with the highest gain among the reported CMOS PAs in V-band. Index Terms-Broadband, CMOS, microwave monolithic integrated circuit (MMIC), power amplifier (PA), 60 GHz, V-band.