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 650μm×700μm, 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 125°C 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.