This paper shows a comparison between several procedures to represent the P
hysical Optics (PO) current density into a hybrid Moment-Method-Physical-Op
tics (NIM-PO) code. Some numerical results demonstrate that a set of basis
functions suitable for the Method of Moments (MM) may be inappropriate to m
odel the PO currents. A new evaluation of the PO operator is proposed. The
radiation can be analytically determined and, since it includes a linear in
terpolation of the phase, it can be applied over large triangular domains.
This allows a drastic reduction of the computational cost, maintaining or e
ven improving the level of accuracy.