Active BALUN with 40 GHz bandwidth at 257 GHz in 130 nm SiGe:C

This paper presents an active BALUN operating around 257GHz with a 40GHz bandwidth. It employs a pseudo-differential cascode stage with a transformer-coupled output and cross-coupled capacitive elimination. Employing multiple enhancements, the common-mode suppression and single-ended to differential conversion are increased. Unaccounted changes during manufacturing are analyzed and included in the simulations. The circuit is manufactured in 130nmSiGe BiCMOS. To the best of the author’s knowledge, it is the first reported active BALUN operating above 200 GHz.