Physical Optics (PO)

The PO solution method is an asymptotic high-frequency numerical method of the same nature as the UTD but based on currents and not rays.

The PO solution method is formulated for use in instances where electrically very large metallic or dielectric structures are modelled. Feko hybridises the current-based accurate MoM with PO including bidirectional coupling between the MoM and PO regions. It discretises a PO region, as it would for a MoM solution, making it a simple task to switch between solution methods. In cases where the MoM part of the problem is electrically large, the PO hybridised with the MLFMM provides an efficient solution.

A practical example for PO would be to calculate the effect on the input impedance of a horn antenna (treated with the MoM) when placed near a large structure (treated with the PO).
Figure 1. PO modelling of a reflector antenna with MoM modelling of the feed.