Dyadic Green's functions for a coaxial line

The eigenfunction expansions of the dyadic Green's functions for a coaxial line have been derived based on the method of
\bar\bar{G}_{m}
, whereby the irrotational vector wave function
\bar{L}
is not needed. A dyadic boundary condition for the discontinuity of the tangential component of
\bar\bar{G}_{m}
has been used to facilitate the derivation of the expression for the electric dyadic Green's function.