New closed-form electromagnetic Green’s functions in layered media

A new methodology is introduced for the development of electromagnetic Green's functions in layered media. This methodology does not require the extraction of the guided wave terms from the spectral-domain Green's function, and does not rely on its approximation by complex exponentials. Instead, a discrete approximation of the governing differential equation in the spectral-domain is used as the vehicle for the development of the spatial Green's function in closed form. Since this new method does not require the development of the spectral-domain Green's function in closed form, it is suitable for the generation of closed-form Green's function in planar inhomogeneous media exhibiting arbitrary variation in their electromagnetic properties in the vertical direction.