The electromagnetic edge wave due to a point source of current radiating in the presence of a conducting wedge

Cylindrical wave expansions for the dyadic Green's functions for electric and magnetic fields of a point source of electric current radiating in the presence of a perfectly conducting wedge are derived using a scalarization procedure developed by Levine and Schwinger. The forms derived from this procedure involve a sum over angular wavenumbers and a continuous spectral integral which may be expressed either as an integration over a longitudinal or a radial spectral variable. Some relationships between these two representations are discussed. The longitudinal spectrum integral has a pair of branch points as its only singularities and may be evaluated asymptotically along a steepest descent path away from one of the branch points. The resulting asymptotic representation is found to agree with an earlier result obtained by Kouyoumjian and Buyukdura. The edge-guided wave interpretation of the asymptotic field is discussed, both in light of the longitudinal spectral representation and of the physical content of the asymptotic representation.