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

All power electronic circuits with state feedback controlled switching can be described as nonlinear time-varying dynamical systems. The occurrence of chaos--where the ripple waveforms become aperiodic--is common in such systems. It is shown here that this natural phenomenon may be effectively used in minimizing electromagnetic interference problems in power electronic circuits. This is because converters operating chaotically tend to spread the spectrum, thereby reducing the interference power at any target frequency. We also present the ways of calculating the average values of state variables and the power spectrum under chaotic operation.

The Modified edge representation (MER) is the concept to be used in the line integral approximation for computing the surface radiation integrals of diffraction. The MER as applied to the physical optics (PO-MER), has remarkable accuracy in the surface-to-line integral reduction even for the curved surfaces and for sources very close to the scatterer. In the discussion of the mathematical foundation for this accuracy, the evaluation of the singularities in the integrand of the PO-MER line integration was left for further study.

This paper presents the Physical Optics field calculation in terms of only line integrations by using the Modified Edge Representation technique (MER), the alternative way of the surface integration. Not only the diffracted fields as in the conventional method of equivalent edge currents (EEC) but also the scattering geometrical optics fields are expressed in terms of the MER line integrals. The far field patterns of parabolic reflector antennas with the defocused dipole feed are discussed and the satisfactory agreement with those obtained by the Physical Optics surface integration is demonstrated.