This paper presents a differential Power Amplifier (PA) for operation in the D-band. The simulated PA has 8 dB/stage at 160 GHz for a total gain of 32 dB, a saturated output power of 11 dBm, a peak power added efficiency (PAE) of 9.8%, and a 3-dB bandwidth of 7 GHz. The PA consumes a power of 112 mW from 1.1 V supply. The PA core area is 0.052 mm2 in 28-nm FD-SOI technology.