Comparison of convergence rates of the conjugate gradient method applied to various integral equation formulations

A comparison is presented of the relative convergence properties of the conjugate gradient method using the three principal integral equations for conducting scatterers: the electric field integral equation (EFIE), the magnetic field integral equation (MFIE), and the combined field integral equation (CFIE). The authors restrict their study to scattering by two-dimensional (cylindrical) bodies (both TM and TE polarization). This enables an easy examination of the convergence behaviour of the conjugate gradient method (CGM) for bodies which are electrically large.<>