  Graphene-based intelligent reflecting surface (GIRS) has been proved to
provide a promising propagation environment to enhance the quality of high
frequency terahertz (THz) wireless communication. In this paper, we
characterize GIRS for THz communication (GITz) using material specific
parameters of graphene to tune the reflection of the incident wave at IRS. In
particular, we propose a GITz design model considering the incident signal
frequency material level parameters like conductivity, Fermi-level, patch width
to control the reflection amplitude (RA) at the communication receiver. We have
obtained the closed-form expression of RA for an accurate design and
characterization of GIRS, which is incomplete in the existing research due to
the inclusion of only phase-shift. The numerical simulation results demonstrate
the effectiveness of the proposed characterization by providing key insights.
