W-band low-power millimeter-wave direct down converter using SiGe HBTs in saturation region

The continuous progress in SiGe:C HBT BiC-MOS process technology has led to HBTs with quite reasonable performance even for a forward-biased base-collector junction. Operation in the associated saturation region enables a significant reduction in the power consumption of high-frequency integrated circuits. This work aims at exploring the design of mm-wave circuits with lowest possible power consumption while maintaining reasonable performance for possible integration into mobile systems where battery lifetime is crucial. A second goal is the evaluation of HBT compact models in saturation and under realistic circuit operation. This paper presents the measured and simulated results of a 94 GHz direct down converter. The supply voltage for the Gilbert-cell based mixer core is as low as 0.7 V.