Patent ID: 8633861

Claim:
A waveguide radiating element having a working frequency that is tunable below a cut-off frequency, the waveguide radiating element comprising a rectangular tube presenting a longitudinal axis and a rectangular mouth on a plane perpendicular to the longitudinal axis; the rectangular mouth comprising an upper edge and a lower edge, as well as lateral edges; and the rectangular tube being partially filled with a MNG meta-material comprised of a number N l of dielectric slabs disposed on parallel planes that are spaced-apart, the number N l of dielectric slabs being a positive integer number >2, the parallel planes being incident on said lower edge of said mouth, each of the number of N l dielectric slabs having engraved on each of their faces a number N SSR of concentric Split Ring Resonator (“SSR”) squares, each of the number N SSR of concentric SRR squares presenting a gap on one of its sides, and the number N SSR of concentric SRR squares being a positive integer value ≧1, wherein: a supply pin has a height h p ; a distance d l between at least one pair of consecutive slabs of the number N l of dielectric slabs is non-uniform along a direction of said lower edge; the number N SSR of SSR squares present an arrangement of the gaps of an outmost square in such a way that, on facing sides of two adjacent slabs, the gaps are rotated with respect to each other, said gaps being rotated at an angle of 0°, or 90°, or 180°, or 270° with respect to an axis α orthogonal to said two adjacent slabs, and the gaps of at least two of said number N SSR of SSR squares are rotated at an angle different from 180°; and the working frequency of the waveguide radiating element is a function of N l , d l , h p , N SSR .