Ricerc@Sapienza

We propose a simple phased-array design based on a Fabry-Perot cavity antenna for the generation of a highly-directive pencil beam steerable along two directions in 3-D space. Each array element generates an element pattern in the far-field obtained through the excitation of a dominant cylindrical TM leaky wave inside the cavity. Hence, the resulting conical pattern is combined with the array factor of a N × N square or circular arrangement of ideal vertical electric dipoles.

We describe the possibility of achieving enhanced radiation performance introducing multiple sources within a two-dimensional structure supporting one or more cylindrical leaky-waves. The device is planar and made by a grounded dielectric slab loaded on top by a periodic arrangement of metallic strips or patches and it is fed by an array of simple, fully integrated, dipoles.

Directive pencil beams scannable in both elevation and azimuth are obtained through a planar phased array placed inside a Fabry-Perot cavity. The key element of the proposed approach is the exploitation of a conical element pattern (EP) with high directivity in elevation, obtained through the excitation of a dominant, weakly attenuated cylindrical TM leaky wave of azimuthal order n = 0 by means of a simple coaxial probe. Then, a highly reduced number N of such sources are arranged to form a phased array radiating directive pencil beams.

A two-dimensional leaky-wave antenna fed by an array of fully integrated sources and able to provide fixed-frequency continuous beam steering through broadside is presented in this contribution. The structure is constituted by a 'bull-eye' leaky-wave antenna fed by a proper arrangement of four surface-wave launchers, whose excitation coefficients are selected to control the beam pointing angle around broadside.