High speeds in a single chip

This article reviews the development and breakthrough of SiGe technologies. SiGe HBTs with transit frequencies ft and maximum oscillation frequencies fmax above 300 GHz and monolithic integrated millimeter-wave circuits based on these HBTs have been developed by several groups. As this paper shows in the overview, the combination of active devices with passive planar structures, including antenna elements, allows single-chip realizations of complete millimeter-wave front-ends.