A 440–540-GHz Subharmonic Mixer in 130-nm SiGe BiCMOS

A subharmonic mixer (SHM), which is measured within the RF range 450-500 GHz, is presented. The SHM uses a single-balanced topology with optimized parameters for gas spectroscopy at 440-540 GHz. The differential RF input of the mixer core is transformed to a single-ended input using a Marchand balun. The mixer is designed using a 130-nm SiGe BiCMOS technology. The mixer shows a measured conversion loss of 8.5 dB and an estimated noise figure of 33 dB at 480 GHz, using -1 dBm local oscillator (LO) power. The conversion loss was quantified to be in the range of 7.5-12.5 dB at 450-500 GHz.