Representation of a Straight Thin Wire in a Lossy Medium and an Oblique Thin Wire in Air for FDTD Simulations

An improved representation of a straight thin wire for a 3-D finite-difference time-domain simulation has been applied to the transient analysis of a straight thin wire in a lossy medium, and its validity has been shown. In this representation, a straight wire having a specified radius is simulated by a straight wire having the equivalent radius 0.199Δs, where Δs is the lateral side length of cubic cells employed, embedded in an artificial parallelepiped medium having modified conductivity (only if it is in a lossy medium), modified relative permittivity, and modified relative permeability. Also, the equivalent radius of a staircase-approximated oblique wire in air has been evaluated, and its thin-wire representation has been discussed.