A Multiband Circularly Polarized SIW-Horn Antenna for Sub-Theraherz Frequencies

This work proposed a circular polarized dielectric loaded substrate integrated waveguide (SIW) <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$H$</tex>-plane sectoral horn antenna. The antenna is a laminated planar waveguide consisting of two metal structures mounted on the top and bottom of a dielectric substrate with an array of metallic vias embedded in the substrate to emulate the vertical walls of a traditional waveguide. A dielectric slab identical to that of the horn and acting as a lens is used at the horn opening to increase the gain. Printed transitions are etched on that slab for matching purposes and to improve the antenna's bandwidth. Circular polarization is obtained by etching a dipole after the transition elements, whereby one arm of the dipole is on the top layer while the other is on the bottom layer. The simulated results are displayed as obtained. They show that the antenna is a multiband antenna with wideband and circular polarization characteristics. The antenna is of high gain and has a high degree of polarization purity. These characteristics make it a good candidate for the 6th generation of mobile communication systems (6 G).