Implementation of the Spherical (Vector) Wave Expansion (SWE) following FEKO definition. Additionally, these derivations are used for numerical stability.
A far-field, vector electric field is used as input. The normalization used will produce the same mode magnitudes/phase as FEKO.
Overall reconstruction error stays below 5% for most applications. Addiitonal testing is needed to see the behaviour for large number of modes and for modes with low magnitudes
