A 60 GHz same-channel full-duplex CMOS transceiver and link based on reconfigurable polarization-based antenna cancellation

This paper describes a direct-conversion 45nm SOI CMOS 60 GHz transceiver for same-channel full duplex applications. A novel polarization-based wideband self-interference cancellation (SIC) technique in the antenna domain is described that can be reconfigured from the IC. In order to achieve the high levels of required SIC, a second RF cancellation path from the transmitter output to the LNA output with >30 dB gain control and >360° phase control is also integrated. The TX and RX share the same LO to reduce the impact of phase noise on SIC. Antenna and RF cancellation together enable >70 dB of total self-interference suppression even in the presence of nearby reflectors. In conjuction with digital SIC impemented in MATLAB, a same-channel full-duplex link is demonstrated over 0.7 m. To the best of our knowledge, this work demonstrates the first fully-integrated full-duplex transceiver front-end and mm-wave link. While not our focus, the transceiver also achieves state-of-the-art saturated output power of +15 dBm, peak TX efficiency of 15.3% and RX NF of 4 dB.