A 94GHz differential power amplifier in 45nm LP CMOS

This paper presents a 94 GHz 4-stage differential transformer-coupled power amplifier with capacitive neutralization. The use of transformers results in excellent common mode isolation between the different stages while providing a good impedance match. The neutralized differential pairs guarantee differential stability. The PA was designed in a 45 nm LP CMOS technology. An output 1 dB compression point of +4 dBm and a gain of 18 dB was measured. The total chip area is 0.43 mm² and the active part consumes only 0.07 mm². The 3 dB bandwidth is 14 GHz. Power consumption is 120 mW from a 1V supply, resulting in a peak PAE of 4.6%.