Near field distribution and far field analysis of H-plane sectoral multi-layer solid dielectric horns

In this paper, near field and far field distribution of H-plane sectoral multi-layer solid dielectric horn antennas has been analyzed theoretically under some simplifying assumptions for TE to X modes. Solution of Helmholtz equation is obtained for TE to X modes using separation of variables technique by assuming the horn to be made of an equivalent homogeneous dielectric material of dielectric constant equal to the equivalent of three dielectrics of slightly differing dielectric constants. On applying the proper boundary conditions i.e. the continuity of the electric and magnetic fields at the interfaces each between a dielectric region and a free space, transcendental equations for the transverse components of propagation constants are obtained. These transcendental equations are solved for the transverse propagation constants, for the fundamental mode and for two higher order modes for the horn of axial length = 6.34 cm and flare angle equal to 43.32°, and for the fundamental mode and for three higher order modes for the horn of axial length = 8 cm and flare angle = 43.32° at 10.2 GHz. The theoretical aperture distributions and far field obtained for these antennas are compared with corresponding experimental ones.