This paper presents a fully integrated 77GHz power amplifier (PA) fabricated in a 0.13 μm SiGe BiCMOS technology. A 4-stages single ended common-emitter topology was utilized to achieve power gain of 19dB at 77GHz with 14.6dBm output power at 1dB compression, saturated power of 16dBm and 12.5% peak PAE. Small signal characteristics show a wideband behavior - Maximal small signal gain of 23dB achieved at 69GHz with 3dB bandwidth of 15GHz (22%) and both input and output matching is better than -10dB from 72GHz to 90GHz. The PA's bias is applied by adjustable bias circuits to provide process and temperature compensation and was measured in room temperature and at 85°C. It consumes a quiescent current of 100mA from a 2V supply at 1dB compression and occupies area of 1.4mm2. © 2010 IEEE.