These Hankel and Bessel functions are not easily calculated analytically unless a computer is used. The electromagnetic software FEKO was carried out to simulate and predict the RCS of a PEC sphere as function of its electrical size as illustrated in Figure 3.4. The method applied herein is an exact solving technique known as the Method of Moments (MoM), was used to simulate the RCS of PEC sphere and compare the results with the Mie series solution for the backscattered of PEC sphere to make sure there is consistency between the results.

The method of moments divides the PEC sphere surface into a collection of discrete patches. For each patch on the surface, the electric and magnetic fields boundary conditions are applied to create an equivalent matrix of induced surface electric and magnetic currents. Each current is defined as a product of a higher order known functional basis with an unknown coefficient, for which the matrix system is solved. Across the surface of the sphere, the total solution of these currents is formed of a combination of these coefficients with their corresponding basis functions.

Then, they will be inserted into Maxwell’s equations to produce the resulting scattered electromagnetic field