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A fast and accurate analysis and synthesis technique for high-gain sub-wavelength 2-D Fabry-Perot leaky-wave antennas (LWA) consisting of two periodic metallodielectric arrays over a ground plane is presented. Full-wave method of moments (MoM) together with reciprocity is employed for the estimation of the near fields upon plane wave illumination and the extraction of the radiation patterns of the LWA. This yields a fast and rigorous tool for the characterisation of this type of antennas. A thorough convergence study for different antenna designs is presented and the operation principles of these antennas as well as the radiation characteristics are discussed. Moreover, design guidelines to tailor the antenna profile, the dimensions of the arrays as well as the antenna directivity and bandwidth are provided. A study on the radiation efficiency for antennas with different profiles is also presented and the trade off between directivity and radiation bandwidth is discussed. Numerical examples are given throughout to demonstrate the technique. A finite size antenna model is simulated using commercial software (CST Microstripes 2009) which validates the technique.Index Terms-Artificial magnetic conductor, high-gain antennas, high impedance surfaces, leaky-wave antennas (LWAs), resonant cavities, sub-wavelength resonators.

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A structure comprising a coupled pair of two-dimensional arrays of oblate plasmonic nanoellipsoids in a dielectric host medium is proposed as a superlens in the optical domain for both horizontal and vertical polarizations. By means of simulations it is demonstrated that a structure formed by silver nanoellipsoids is capable of restoring subwavelength features of the object for both polarizations at distances larger than half-wavelength. The bandwidth of subwavelength resolution is in all cases very large (above 13%).A conventional lens can refocus the far field by means of cancelling the phase that light acquired when propagating away from the source. The resolution in this case is fundamentally restricted for features smaller than half the wavelength. Subwavelength details are contained in evanescent waves, which are characterised by spatial frequencies larger than the free space wavenumber and therefore cannot propagate in the far zone. Based on materials characterised by negative index of refraction 1 , a device that can restore subwavelength features in the near field, the socalled superlens, was proposed 2 . However, artificial negative refractive index layers operating as a superlens are very sensitive to losses, spatial dispersion and are extremely narrow-band [3][4][5]