The Array Scanning Method for the computation of ID-periodic 3D Green's functions in stratified media

ID-periodic structures embedded in stratified media have been studied for some time in the framework of leaky-wave antennas [1], microwave frequency-selective devices, etc.; they have recently received considerable attention, due to their possible application for the realization of metamaterial-like structures [2]. Their numerical analysis can be performed through both approximate [3] and rigorous [4] methods. With this aim, in [4] a complete formulation is proposed and described to solve integral equations in a stratified ID-periodic environment. In particular, the ID-periodic multilayered Green's functions are defined as one-dimensional sums of harmonics, each one computed in a suitable way according to its leaking regime (bound harmonic, surface-leaky harmonic, or space-leaky harmonic). Here, an alternative approach to the computation of these Green's functions is proposed and validated, by using the Array Scanning Method (ASM), a simple and accurate representation of electromagnetic fields in periodic structures excited by nonperiodic sources [5], [6]. The ASM consists of an integral superposition of auxiliary-periodic quantities, each excited by a phased array of the sources where the phasing varies in the first Brillouin zone: © 2010 IEEE