Dispersive analysis of a dual-layer planar structure for leaky-wave antenna applications

The dispersive features of a 2-D planar leaky-wave antenna constituted by an annular slot grating on a dual-layer grounded dielectric slab are presented in this contribution. A well-established in-house method-of-moments dispersion code has been suitably generalized to account for a multi-layer substrate and to assist in the characterization of the corresponding linearized structure. Validations are performed through full-wave simulations developed on state-of-the-art commercial software applying a hybrid Bloch-wave analysis on a finite number of unit cells; then, a parameterization study on the thickness of the superstrate is performed. The proposed analysis provides useful information about both phase and attenuation constants of the leaky mode supported by the structure as well as on the behavior of the open-stopband that characterizes this class of structure.