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.