Predicting far-field RCS from near-field data based on MOM

A technique to predict far-field RCS from near-field data is described. The method utilizes near-field data to determine equivalent sources over a fictitious surface which encompasses the target made by perfect electric conductor (PEC) and these sources are used to ascertain the far-field RCS. An electric field integral equation (EFIE) is developed to relate the near-field to the equivalent sources. RWG basis function is involved and makes the EFIE simple. The equivalent sources can be expanded by RWG basis function according to method of moments (MOM) procedure. The integral equation can be transformed into a matrix with the equivalent sources decoupling from the equation. The matrix equation is solved with the least squares techniques. Numerical simulation of this technique is presented. The results of the equivalent sources show high accuracy compared to the scattering RCS calculated by the software FEKO.