Comparison on phase noise in common-source cross-coupled pair and Armstrong differential topologies

This paper reports comparative analyses of phase noise in common-source cross-coupled pair and Armstrong LC differential oscillator topologies designed in 28 nm CMOS technology for operating frequencies of 1 and 10 GHz. The Impulse Sensitivity Function is used to carry out qualitative and quantitative analyses of the phase noise exhibited by each circuit component in each topology. The analyses show that the lowest phase noise is exhibited by the differential Armstrong topology. Additionally, the results show the impact of flicker noise on phase noise performances.