Overview of recent advances in the electromagnetic field solver FEKO

In this paper, an overview of the most recent advances for two high frequency solvers and their hybrid combinations with full wave solvers in the computational electromagnetics code FEKO is given. These are improvements to the Ray-Launching Geometrical Optics (RL-GO) method, and the hybridisation between the Multilevel Fast Multipole Method (MLFMM) and Physical Optics (PO) and its large element version LE-PO. The ray-tracing has been accelerated for RL-GO by using a kd-tree based ray-triangle intersection algorithm and an adaptive ray-launching scheme, where the latter also reduces the memory consumption. Moreover, it is shown that curvilinear meshing for RL-GO leads to more accurate results when objects with a curved surface are involved. An iterative MLFMM/PO or MLFMM/LE-PO hybrid scheme with bi-directional coupling between the two methods is also introduced for extremely large structures, drastically reducing the memory and run-times used. Both RL-GO and the MLFMM/PO or MLFMM/LE-PO hybrid methods are validated and compared with other numerical methods, where the agreement is very good.