Derivation of diffraction coefficients from complex-source beam solutions to canonical problems

The spherical-multipole analysis in sphero-conal coordinates in combination with a complex-source beam as the incident field has been utilized to derive the scattered electromagnetic far-field of a PEC plane angular sector. That canonical problem is of particular practical interest as many structures contain edge-like elements which cannot be treated by common asymptotic high-frequency techniques. The numerical evaluation yields exact and convergent spherical-multipole results which are ready for use in GTD/UTD frameworks.