Millimeter-Wave Sources at 60 and 140 GHz by Magnetic-Plasmon-Waveguide-Based In-Phase Coupled Oscillator Network in 65-nm CMOS

High output power density millimeter-wave (mm-wave) signal sources are demonstrated at 60 and 140 GHz by a magnetic plasmon waveguide (MPW) based in-phase coupled oscillator network (CON) in 65-nm CMOS. Each oscillator unit-cell is designed by an MPW-based low-loss inter-digital zero-phase coupler (ZPC). With multiple in-phase coupled ZPC unit-cells, a high output power mm-wave signal is generated at the center of the CON by an in-phase power combination. A 60-GHz CON-based signal source is implemented with four in-phase CON unit-cells at 60 GHz in a compact core chip area of ${\text {0.11 mm}}^{2}$ . It is measured with 2-mW peak differential output power, 2.2% power efficiency, ${\text {18.2-mW/mm}}^{2}$ output power density, $-{\text {113.9-dBc/Hz}}$ phase noise at 10-MHz offset, and 15.8% frequency tuning range (FTR) centered at 63.1 GHz. Moreover, a 140-GHz signal source is implemented by the combination of second-order harmonics of four in-phase coupled ZPC unit-cells at 70 GHz in a compact core chip area of ${\text {0.13 mm}}^{2}$ . It is measured with 3.5-mW peak output power, 2.4% power efficiency, ${\text {26.9-mW/mm}}^{2}$ output power density, $-{\text {104.9-dBc/Hz}}$ phase noise at 25-MHz offset, and 9.7% FTR centered at 133.5 GHz.