A 16.6-to-34.1 GHz Dual-Core Quad-Mode Oscillator Achieving 202.3 dBc/Hz FoMT in 65nm CMOS

This work presents a millimeter-wave (mm-wave) dual-core quad-mode oscillator incorporating a switch-less tertiary loop to extend the frequency tuning range (FTR) without introducing additional switch loss or parasitic. The design couples two identical transformer-based dual-band (low- and high-frequency) voltage-controlled oscillators (VCOs), which are configurable in either even or odd modes via mode switches. In the high- and low-frequency band, the switch-less tertiary loop functions as an open circuit in the even mode and a short circuit in the odd mode, enabling four distinct frequency modes. Fabricated in a 65-nm CMOS process, the proposed oscillator achieves an FTR from 16.6 to 34.1 GHz, with phase noise ranging from −122.4 to −130.0 dBc/Hz at a 10-MHz offset, while consuming 9.5–11mW of power. This results in a peak FoM of 185.5 dBc/Hz and FoM_T of 202.3 dBc/Hz.