Contents I. Introduction
The analysis of wire structures is the simplest three-dimensional (3-D) electromagnetic problem. Many metallic objects can be approximated by thin-wire structures. In addition, since conducting surfaces can be modeled as wire grids, many general 3-D conductors can also be simulated through a set of wire grid models. The problem of time-harmonic radiation of thin wire involves solution of the electric-field integral equation (EFIE) [1]. To numerically solve the EFIE, one initially expands its unknown current by a set of basis functions. Then, application of appropriate boundary conditions reduces the problem to a matrix equation [1]. In this discretization scheme, known as the method of moment (MoM), a dense matrix equation usually results due to the integral operator. The use of wavelet basis functions [2] in the MoM [3]–[14] yields to a sparse matrix equation for which employing sparse storage schemes and fast sparse-based iterative solvers drastically reduces memory requirement and computational time, especially in large-scale problems [15].