Method of Moment Analysis of Carbon Nanotubes Embedded in A Lossy
Dielectric Slab Using A Multilayer Dyadic Green's Function
Abstract
Modeling the electromagnetic response of carbon nanotube (CNT)
reinforced composites is inherently a three dimensional (3D) multi-scale
problem that is challenging to solve in real-time for nondestructive
evaluation applications. This article presents a fast and accurate
full-wave electromagnetic solver based on a multi-layer dyadic Green’s
function approach. In this approach, we account for the effects of the
dielectric slab, where the CNTs are embedded, without explicitly
discretizing its interfaces. Due to their large aspect ratios, the CNTs
are modeled as arbitrary thin wires (ATWs), and the method of moment
(MoM) formulation with distributed line impedance is used to solve for
their coupled currents. The accuracy of the inhouse solver is validated
against commercial method of moment (MoM) and finite element method
(FEM) solvers over a broad range of frequencies (from 1 GHz to 10 THz)
and for a wide range of dielectric slab properties. Examples of 100nm
long vertical and horizontal CNTs embedded in a 1 μm thick lossy
dielectric substrate are presented. The in-house solver provides more
than 50 ✕ speed up while solving the vertical CNT, and more than 570 ✕
speed up while solving the horizontal CNT than a commercial MoM solver
over the GHz to THz frequency range.