A Broadband Low Profile SIW H-Plane Horn Antenna with Improved Performance

Abstract

This paper is presenting a broadband, low-profile ($0.008 \lambda_{0}$) substrate-integrated waveguide (SIW) H-plane horn antenna with the reduced side lobes and improved front-to-back ratio (FTBR). This is achieved implementing three rectangular slots near the coaxial feed. The hexagonal slots in front of the horn aperture are used to improve impedance matching. The measured fractional impedance bandwidth of 29.5% (3.25 GHz), the maximum gain of 5.52 dBi (minimum: 2.85 dBi), the maximum radiation efficiency of 95.99 %, the FTBR of 15.83 dB, and the low cross-polarization level have been achieved at the frequency of 9.85 GHz.