An Equivalent Circuit Model for Graphene-Based Terahertz Antenna Using the PEEC Method

The electromagnetic (EM) characterization of graphene under general EM environments is becoming of interest in the engineering and scientific research fields. However, its numerical modeling process is extremely cost prohibitive due to the huge contrast between its thickness and other dimensions. In this work, for the first time, the EM features of graphene are characterized by a circuit model through the partial element equivalent circuit (PEEC) method. The atomically thick graphene is equivalently replaced by an impedance boundary condition. After incorporating the PEEC method, a novel surface conductivity circuit model is derived for graphene. A physical resistor and inductor are added into the conventional PEEC cell due to the dispersive conductivity property of graphene. The proposed novel method significantly reduces the memory and CPU time consumption for general graphene structures when compared with standard numerical finite element method (FEM) or finite difference (FD) methods, where 3-D meshing is unavoidable. This model also transforms the surface conductivity of graphene into a vivid circuit, and physical properties of the material can be conveniently obtained, such as radiation, scattering, and resistance properties, when compared with method of moments (MOM). In addition, the radiation and scattering calculation by MOM entail the cumbersome steps of defining a bounding surface and implementing a multidimensional integrand, while in PEEC, these complications are entirely bypassed by the concise vector-matrix-vector product (VMVP) formulas. To validate the introduced algorithm, various numerical examples are presented and compared with existing references.