  The bias-dependence of input referred low-frequency noise (LFN), SVG, is a
considerable facet for RF circuit design. SVG was considered constant in
silicon transistors but this was contradicted by recent experimental and
theoretical studies. In this letter, the behaviour of SVG is investigated for
single-layer graphene transistors based on a recently established physics-based
complete compact LFN model. A minimum of SVG is recorded at the bias point
where maximum transconductance is located which coincides with the peak of the
well-known M-shape of the normalized output LFN and the model precisely
captures this trend. Mobility fluctuation effect increases SVG towards to lower
currents near charge neutrality point (CNP) while carrier number fluctuation
and series resistance effects mostly contribute away from CNP; thus, SVG
obtains a parabolic shape vs. gate voltage similarly to CMOS devices.
