A Quantitative Phase Noise Study of VCOs from RF to Millimeter Wave Frequencies

This paper presents an analysis of phase and jitter noise in crossed-coupled voltage-controlled oscillators (VCOs). The topology under test was designed using a 65 nm RF-CMOS process, oscillating in three carrier frequencies: 5 GHz, 15 GHz, and 24 GHz. The carrier frequency is determined by adjusting the values of the LC tank, while ensuring consistent transistor sizing and bias conditions for accurate performance comparison. A thorough simulation analysis is conducted to examine and compare the phase and jitter noise performance in all three VCOs. The measured phase noise values, at a 1 MHz offset from the carrier, were -108.43 dBc/Hz at 5 GHz, -96.97 dBc/Hz at 15 GHz, and -91.79 dBc/Hz at 24 GHz while, the dominant noise sources of each oscillation frequency were extracted, providing a better visualisation of the noise impact relative to the carrier frequency.