Computation of layered mixed potentials for the accurate and efficient analysis of 1-D periodic printed leaky-wave antennas

The design techniques of leaky-wave antennas usually require complex analysis methods for the rigorous characterization of the radiating structures as a function of the various geometrical and physical parameters involved. An increasing number of such antenna topologies are based on planar stratified configurations with suitable inclusions of periodic metallic perturbations. The prediction of the leaky-wave parameters (i.e., phase and leakage constants, etc.) is a difficult task to achieve in an accurate and efficient fashion. In this frame, the present contribution is focused on the computational aspects related to an integral-equation approach to the problem based on a mixed-potential formulation. By means of specific asymptotic extractions, powerful acceleration techniques of the relevant scalar and dyadic 1-D periodic Green’s functions are proposed and tested, which are suitable for the analysis of printed structures with both planar and vertical elements and can take into account the presence of improper leaky waves supported by the periodic layered structures. Results of the complex wavenumber dispersion features are provided and discussed for various significant types of 1-D periodic printed leaky-wave antennas.