Electromagnetic modeling and EMC performances of graphene-based micro-/nanostructures

Nano-electromagnetic compatibility (EMC) is a new research field aimed at bridging the gap between nanotechnology and EMC. This new field is interdisciplinary and covers several fundamental EMC topics, such as electromagnetic (EM) shielding and absorption. Scope of this chapter is to introduce the electromagnetic modeling and to discuss the EMC performances of graphene-based micro/nano structures. The frequency-dependent conductivity of an isolated graphene sheet is modeled through the use of the Kubo’s general formulation and of approximate expressions of the intraband and interband conductivity terms. The modeling of graphene multilayer, consisting of homogeneous graphene monolayers separated by dielectric interlayers excited by a plane wave with normal incidence, is investigated. The transmission matrix approach is applied to obtain the overall transmission matrix of the graphene/dieletric laminate (GL) up to low-terahertz frequency range. An equivalent single layer (ESL) of the GL is represented in the low-gigahertz frequency range and in low-terahertz regime applying the effective medium approximation (EMA), which models each graphene/dielectric bilayer as a homogeneous anisotropic medium. The shielding performance of electrically doped GL against an impinging EM plane wave with normal incidence is computed in the low-gigahertz band assuming the hypothesis of short-line. The frequency spectrum of the shielding effectiveness of the GL is obtained using both the rigorous multilayer and approximate ESL methods. Moreover, shielding performances of chemically doped GLs are computed in a reverberation environment in the low-terahertz frequency band. Modeling of graphene-based absorbing multilayer structures made by a two-period dielectric Salisbury screen is developed, and the reflection coefficient of electrically doped GLs is represented in both the low-gigahertz and low-terahertz frequency bands. The frequency spectra of the minimum reflection coefficient of different adaptive absorber screens are computed. Finally, the EM modeling of graphene sheets biased with magnetic or electric static fields is treated. Closed-form expressions describing the tensorial conductivity of the biased monolayer graphene are provided together with simple expressions of the components of the electric field transmission coefficient. The simulation model is applied in order to highlight the low-gigahertz gyrotropic, shielding and sensing properties in case of normally incident plane wave.