Highly directive 2-D leaky wave antennas based on double-layer meta-surfaces

This paper presents a fast and accurate analysis and synthesis technique for highly directive 2-D Fabry-Perot leaky-wave antennas (LWA) consisting of two periodic metallo-dielectric arrays over a ground plane. Full-wave method of moments (MoM) together with reciprocity is employed for the estimation of the near fields upon plane wave illumination and the radiation patterns of the LWA. Two antenna designs are studied using this rigorous technique. A subwavelength antenna with λ/4 profile is characterised. The antenna profile, the dimensions of the arrays as well as the antenna directivity, bandwidth and radiation efficiency are investigated. In addition, an antenna with broadband performance is presented. The operation principle of this configuration is discussed. The proposed technique and a ray optics model are used in order to demonstrate the bandwidth enhancement.