Chapter 2 - Wire Structures: TDIE Solution

Abstract

Many practical geometries can be modeled as wire-grid structures to accurately compute the radiation pattern or radar cross-section. These models usually use thin wires for modeling purposes that result in evaluating simple one-dimensional integrals in the numerical solution procedure. Thus, the algorithm developed using a thin-wire approximation is very efficient from a computational point of view. There are several computer codes available based on wire-modeling techniques, both in the frequency and in the time domain. All these codes are very popular and currently used in a variety of situations to model complex bodies. To develop an efficient, general-purpose wire-grid modeling algorithm, whether in the time domain or in the frequency domain, some basic steps are required. The chapter discusses detailed numerical procedures to calculate the transient electromagnetic scattering from thin-wire structures by solving the electric field time domain integral equation. The implicit solution method is also described as an alternative to overcome the instability problem. It is observed that the implicit solution has a faster damping rate, thereby eliminating the possibility of instabilities.