An ultra-fast frequency shift mechanism for high data-rate sub-THz wireless communications in CMOS

Various approaches are being considered to address the demand for high-throughput (Gb/s) point-to-point wireless communication systems in 5G infrastructure and sub-THz transceivers. Two fully integrated CMOS wireless transmitters with frequency shift keying (FSK) modulation were prototyped in a standard 55 nm SiGe process. Benefiting from the coupled oscillator loop system, the single channel data rate up to 10 Gb/s wireless link (limited by measurement equipment) was demonstrated. The proposed coupled oscillator loop system enables instantaneous frequency shift in an ideal situation, which resolves overshoots/undershoots and long frequency settling issues in the conventional varactor-based LC voltage controlled oscillator. The measured single channel data rate is around 5× higher than the previously published CMOS/BiCMOS FSK transmitter.