A 117-155-GHz SiGe HBT D-Band Subharmonic Mixer Utilizing a Novel 180 degrees Hybrid Coupler

This letter presents a D-band subharmonic down-conversion mixer for next-generation communications and imple-mented in a 90-nm SiGe BiCMOS technology. The design consists of a cascoded push-push doubler and a wideband transimpedance amplifier (TIA), and it utilizes a novel, 180? hybrid coupler topology to achieve wide bandwidth, moderate conversion gain (CG), and power consumption. The subharmonic mixer achieves a peak in-band gain of 5.1 dB and a bandwidth of 38 GHz at a center frequency of 136 GHz. The subharmonic mixer utilizes a fixed local oscillator (LO) of 2 dBm at 57.5 GHz and consumes 50.8 mW of dc power. The core die area of the subharmonic mixer is 0.9 x 0.5 mm2. This mixer achieves highly competitive performance in terms of CG, bandwidth, and power consumption with respect to D-band subharmonic mixers demonstrated in silicon.