Biconical antenna with inhomogeneous dielectric lens for UWB applications

The improvement of the ultra-wideband (UWB) biconical antenna directional characteristics at the upper part of the bandwidth by filling the aperture with the inhomogeneous dielectric lens is discussed in this Letter. The inhomogeneity of the filling was achieved by the complex three-dimensional configuration of the air gaps and the dielectric with constant permittivity. The distribution law of permittivity in the aperture was obtained in the geometrical optics approximation using the law of Lihtenekker for finely dispersed composition of substances with different dielectric constants. The numerical simulations and the experimental measurements of the biconical antenna characteristics have been carried out and the results are presented. The application of the proposed method allows to reduce the level of lateral radiation and to increase the antenna gain and bandwidth. The technique for the lens manufacturing by using 3D printing technologies is presented.