SiGe BiCMOS 65-GHz BPSK transmitter and 30 to 122 GHz LC-varactor VCOs with up to 21% tuning range

This work presents a systematic study of millimetre-wave, low-noise, widely-tuneable differential Colpitts VCOs. A design methodology was developed and validated experimentally over thirteen different varactor-tuned (VCO) and fixed-frequency L-C oscillators spanning the 30-GHz to 122-GHz frequency range. All circuits employ accumulation-mode n-MOS varactors, and multi-turn on-chip inductors. The 35-GHz and 60-GHz oscillators achieve phase noise of -112.7 dBc and -104 dBc/Hz, respectively at 1-MHz offset and deliver +4 dBm differential output power while a push-push implementation demonstrates 15-GHz (21%) tuning range from 63.5 GHz to 78.5 GHz. A directly-modulated, 65-GHz binary phase shift keying (BPSK) transmitter is also implemented.