Highly Efficient and Well-Matched Empty Substrate Integrated Waveguide H-Plane Horn Antenna

Abstract

In this letter, an empty substrate integrated waveguide H-plane sectorial horn antenna is presented. The antenna is integrated within a planar substrate and is fed by means of a microstrip transmission line. It is composed of a partially empty substrate layer stacked between two cover metallic plates. Results obtained for a prototype designed and fabricated at Ku-band show a measured efficiency close to 90% and matched responses. No extra loading elements are needed in order to reduce reflection at the end of the aperture conversely to previous designs. Moreover, the structure is quite simple and cheap and does not depend on substrate characteristics, i.e., dielectric permittivity or loss tangent. This new methodology for manufacturing substrate integrated antennas without dielectric considerably improves the performance of conventional substrate integrated horn antennas.