This paper presents a compact and lightweight Ku-band dielectric-loaded H-plane sectoral horn antenna, using the substrate integrated waveguide (SIW) technology, suitable to be utilized as an element of a steerable multi-sector antenna with the ability of scanning a full 360‹ on the horizon. A dielectric loading together with metallic strips in front of the SIW horn aperture are utilized to optimize the performances in terms of bandwidth, gain and front]to]back ratio (FTBR). To experimentally demonstrate the performance of the proposed design, a three]element prototype, intended later to be a part of an eight]sector antenna, has been fabricated. The measurement process of different characteristics of the prototype is discussed in detail and a comparison between simulated and measured results is given.