Input-Referred Low-Frequency Noise Analysis for Single-Layer Graphene FETs

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