A 230.5–238.8-GHz magnetically coupled triple-push oscillator with inductive tuning for data transmission in 45-nm CMOS

A scalable coupled triple-push voltage-controlled oscillator (VCO) based on inductor switching is analyzed and proposed for data transmission via binary frequency shift keying (BFSK) at sub-terahertz (THz) frequencies in 45nm predictive CMOS bulk technology. Inductive switching enables better quality factors above 100GHz due to the increasing losses associated with capacitors. Novel inductor switching technique is proposed in order to enable easy coupling and wide tuning range at the same time for data transmission above 200GHz. Simulation results suggests that 12.3Gbps data rate is possible to be achieved. -12.4dBm output power is achieved with only a variation of 0.2dB in 7.4GHz bandwidth. Oscillation frequency can be tuned from 224GHz to 231.4GHz for single core VCO. Power consumption is 15.5mW for one core. The proposed oscillator is easy to magnetically couple from gate inductors to generate higher output powers depending on the transmission distance and losses. Two coupled VCO is implemented as a proof of concept and reaches up to -10.5dBm output power with a bandwidth of 8.25GHz. To the authors knowledge, this is the first VCO above 200GHz that uses inductor switching and BFSK.