80/160-GHz Transceiver and 140-GHz Amplifier in SiGe Technology

A dual-band mm-wave imaging transceiver, transmitting and receiving simultaneously in the 80-GHz and 160-GHz bands, is fabricated in SiGe HBT technology. The circuit features an 80-GHz quadrature Colpitts oscillator with differential outputs at 160 GHz, a double-balanced Gilbert-cell mixer, and two broadband 70-270 GHz vertically stacked transformers for single-ended to differential conversion. The differential down-conversion gain is -20.5 dB for RF inputs between 70 GHz and 94 GHz and -23.5 dB for inputs in the 150-170 GHz band. The oscillator generates a total of +5.5 dBm at 80 GHz and -5 dBm differentially at 160 GHz. The transceiver with pads occupies 650 mum times 700 mum, is biased from 3.3 V, and consumes 280 mW. A 5-stage amplifier with 17 dB gain and -1 dBm output compression power at 140 GHz is also fabricated and characterized over temperature up to 125degC and over 14 different wafer splits. These results demonstrate for the first time the feasibility of SiGe BiCMOS technology for products in the 100-160 GHz range.