  The standard solution to time-harmonic electromagnetic scattering problems in
homogeneous layered media relies on the use of the electric field dyadic
Green's function. However, for small values of the governing angular frequency
$\omega$, evaluation of the electric field using this Green's function exhibits
numerical instability. In this short note, we provide an alternative approach
which is immune from this low-frequency breakdown as $\omega \to 0$. Our
approach is based on the generalized Debye source representation of Maxwell
fields. Using this formulation, the electric and magnetic fields gracefully
decouple in the static limit, a behavior similar to that of the classical
Lorenz-Debye-Mie representation of Maxwell fields in spherical geometries. We
derive extensions of both the generalized Deybe source and Lorenz-Debye-Mie
representations to planar geometries, as well as provide equations for the
solution of scattering from a perfectly conducting half-space and in layered
media using a Sommerfeld-like approach. These formulas are stable as $\omega$
tends to zero, and offer alternatives to the electric field dyadic Green's
function.
