This paper presents the design and measurements of a broadband amplifier realized in a 0.13-?m SiGe BiCMOS technology. The amplifier is based on a fully differential cascode topology for achieving high gain and good isolation. To improve the bandwidth T-type input and output matching networks with four reactances are utilized. In order to investigate the wideband performance of the designed matching network a single-stage is fabricated which shows a measured 3-dB bandwidth of 46 GHz. By utilizing three stages a measured peak gain of 20dB is achieved at 160-GHz, while consuming a DC power of 132 mW. The amplifier demonstrates a 3-dB bandwidth of 40 GHz from 140 to 180 GHz and hence achieves a gain-bandwidth product (GBW) of 400 GHz which is among the highest in the state-of-the-art in this frequency range.