A 10-GHz-Band Voltage-Controlled Oscillator Using Harmonic Shaping to Achieve a 184.9dB Figure-of-Merit for Ultra-Low-Jitter PLL Applications

Abstract

This work presents a 10 GHz band voltagecontrolled oscillator (VCO) using harmonic shaping, optimized for ultra-low-jitter phase-locked-loop applications. The proposed oscillator utilizes a transformer-coupled resonant network that simultaneously shapes the voltage waveform and enhances tank selectivity at multiple harmonic frequencies. By strengthening the second-harmonic voltage component, the oscillator exhibits an extended low-sensitivity region over the oscillation period, reducing phase perturbations introduced by the active devices. As a result, both close-in and far-out phase noise are effectively suppressed without additional filtering or common-mode resonance circuits. Operating at 10.8 GHz, the prototype achieves phase noise levels of −106.9 dBc/Hz and −130.1 dBc/Hz at 1 and 10 MHz offsets, respectively, while consuming 3.9 mW from the supply.