A 195–245 GHz Direct Up-Conversion Mixer with Wideband Active Balun

This paper presents a sub-Terahertz modified double-balanced Gilbert mixer in 130 nm SiGe BiCMOS process. An active transconductance balun is designed for supporting single ended large bandwidth baseband signal input. The active balun consists of a common-emitter (CE) and a common-base (CB) structure, the negative capacitor at input node of CB stage cancels the parasitic capacitor of CE stage and bias circuit. Therefore, the active balun achieves a large bandwidth from DC. A transformer-based balun is used for LO port matching and single to differential conversion. At RF port, The impedance transformation using transformer and marchand balun to achieve wide RF bandwidth. The proposed up-conversion mixer achieves 3-dB bandwidth form 195 GHz to 245 GHz. The peak conversion gain (CG) is −6 dB, with output referred 1 dB compression point (OP1dB) of −16 dBm. The Mixer is driven by a −4 dBm LO signal. The LO-to RF leakage rejection is 30 dB. The power comsumption is 16 mW.