A 59-to-276-GHz CMOS Signal Generator Using Varactor-Less VCO and Dual-Mode ILFD

An ultrawideband millimeter-wave (mm-Wave) and subterahertz (sub-THz) signal generator is proposed leveraging a varactor-less quad-band voltage-controlled oscillator (QB-VCO), a dual-mode injection-locked frequency divider (DM-ILFD), a power-efficient injection-locked oscillator (ILO) as a driver, and self-mixing-based frequency multipliers for frequency extension. A switched-quadruple-coil transformer is proposed to vary the inductances of the resonant coils in the transformer tank to improve the frequency tuning range of the varactor-less QB-VCO. Besides, a locking-range-enhancement technique is proposed for the DM-ILFD. Implemented in a 65-nm CMOS process, the proposed mm-Wave and sub-THz signal generator achieves a record frequency tuning range from 58.8 to 275.6 GHz with 10-MHz offset phase noise from -115.8 to -89.2 dBc/Hz, while consuming 54 mW and occupying a core area of 0.65 mm
²
, corresponding to a FoM
_T
of -190.4 dBc/Hz.