Dual‐Band Circularly Polarised Asymmetric Linear‐Tapered Horn Antenna for Feeder of Synthetic Aperture Radar Onboard Microsatellite

• DOI: 10.1049/mia2.70006
• Publication Date: 2025-03-12T03:46:47Z
• Authors: Derry Permana Yusuf; Josaphat Tetuko S...; Yuki Yoshimoto; Steven Gao; Koichi Ito

ABSTRACTThis paper presents a novel dual‐band waveguide‐fed circularly polarised (CP) horn antenna for the feeder of synthetic aperture radar (SAR) onboard microsatellite. The proposed horn antenna consists of an asymmetric linearly tapered slot and a waveguide feed. The C‐/X‐band left‐hand circular polarisation (LHCP) design was simulated, and the 3D‐printed prototype was fabricated to validate the simulation and measured in an anechoic chamber. The measured circularly polarised (CP) antenna can achieve dual‐band operations with a 3 dB axial ratio bandwidth of 40% (5–6.5 GHz; 8.5–10 GHz), VSWR less than 1.4 in the operating band and a peak gain of 13.6 dBic (5.3 GHz) and 18.5 dBic (9.4 GHz). The measured half‐power beamwidth (HPBW) at C‐band and X‐band frequencies in the xz‐plane and yz‐plane are achieved at 26°/37° and 18°/23°, respectively. The proposed antenna offers several advantages over current CP antenna designs, including simpler design, low‐cost manufacturing, better impedance matching, wider AR bandwidth and lower sidelobe levels.