A 0.083-mm2 25.2-to-29.5 GHz Multi-LC-Tank Class-F234 VCO With a 189.6-dBc/Hz FOM

A compact multi-LC-tank Class-F
₂₃₄
voltage-controlled oscillator (VCO) for mm-wave applications is reported. It features an inductive multiplier inside the positive feedback loop to suppress the effective noise factor of the MOS devices. Also, by pseudo-squaring the drain-voltage waveform of the MOS devices via 2nd, 3rd, and 4th harmonic peaking, we obtain a lower impulse-sensitivity-function rms value. Prototyped in 65-nm CMOS, the VCO at 28 GHz shows a phase noise of -114.72-dBc/Hz at 1-MHz offset, while consuming 6.6 mW at 0.55 V. The tuning range is 15.7% (25.2-29.5 GHz) and the chip area is 0.083 mm
²
.