Summary: This paper presents a wideband differential amplifier operating at 141GHz in 40-nm CMOS. It is composed of five differential common source stages with cross-coupled capacitors. A small-signal gain of 20dB and a 3-dB bandwidth of 22GHz are achieved. It consumes 75mW from a 0.94-V voltage supply. The die area with balun and pads is 945×842µm2 and the size of the core not including input/output matching networks is 201×284µm2. The small core area is made possible by using a refined “fishbone” layout technique.