Comparative Analyses of Phase Noise in 28 nm CMOS LC Oscillator Circuit Topologies: Hartley, Colpitts, and Common-Source Cross-Coupled Differential Pair
Figure 5
PN versus frequency offset for the three oscillator circuit topologies, obtained through the ISF for a 1 μA current impulse and direct plot from PSS and periodic noise (Pnoise) SpectreRF simulations, for the oscillation frequency of 10 GHz. The flicker and thermal noise contributions to the overall PN are also plotted in order to identify the PN frequency corner. (a) Colpitts: the PN corner is at the frequency offset of 3.1 MHz. (b) Hartley: the PN corner is at the frequency offset of 5.7 MHz. (c) Common-source cross-coupled differential pair: the PN corner is at the frequency offset of 7.5 MHz.
