High-gain H-plane SIW horn antenna loaded with dielectric slab for ku band low RCS applications

Abstract

This article presents the design, simulation and experimental measurements of an H-Plane substrate-integrated waveguide (SIW) Horn Antenna Loaded with FR-4 Slab for Low RCS (radar cross section) applications like defence sector at Ku band (12-16GHz). The design facilitates high gain and good impedance bandwidth (IBW). Also, the proposed structure has simple feed, planar structure with low-cost FR-4 substrate as dielectric material and decomposed into two parts. The former part of the antenna is the feeding part, which consists of two metallic plates filled with air substrate and a 90-degree corner reflector designed by shortening the metallic plates. The later part of the antenna is loaded with the FR-4 substrate that enhance the peak gain of the structure significantly. A simple coaxial probe is employed for the excitation of the corner reflector antenna. After the design is conferred by simulations, the same is fabricated and the performance measured experimentally. The experimental results are in close agreement with the simulated results. The design has yielded a 10 dB bandwidth of 30% (11.6-16GHz), and a stable endfire radiation pattern over the entire bandwidth with a peak gain of 18.5 dBi at 14GHz. Also, the design has F/B ratio > 20 dB over entire 10 dB bandwidth. Moreover, the antenna produced low RCS<20 dB(m2) from -30 degree to +180 degree of elevation angle. Therefore, antenna can’t easily be detected from the radar system and suitable for defence applications.