Broadband Circularly Polarized SIW-Based H-Plane Horn Antenna for X/Ku Band Applications

Abstract

In this paper, a circularly polarized (CP) substrate-integrated waveguide (SIW)-based H-plane horn antenna with broader impedance bandwidth and higher peak realized gain (PRG) for armature satellite services (X-band, 8-12 GHz) and broadcast satellite (Ku-band, 12-18 GHz) applications is presented. A tapered microstrip transition is used in the feeding section to obtain the broadband characteristics. In addition, the feeding component of the antenna utilizes three quarter-wavetransformers to enhance impedance matching and widen the bandwidth. To generate the CP, two rows of rectangular slots are etched from both the top and bottom metal surfaces of the design. The antenna is designed, fabricated, and tested. The measured fractional impedance bandwidth of 41.6%, the 3-dB axial ratio bandwidth of 3.8 GHz, the maximum PRG of 6.95 dBic, the maximum radiation efficiency (simulated) of 87 %, and the cross-polarization level below -40 dB have been achieved at the center frequency of 13.2 GHz. © 2024 IEEE.