Wideband Circularly-Polarized Horn in a X-Band Spatially-Fed Array Antenna

The wideband horn antenna operating in circular polarization (CP) is essential in various applications. In this study, the horn is excited by the standard rectangular waveguide at X-band (WR90) in linear polarization. The wave travelling in the waveguide flange reaches a transition guiding the wave and converting it from linear polarization to circular polarization. The simulation results show wideband operation of the horn that has axial ratio (AR) below 3-dB in a range spanning from 8.51 GHz to 12.04 GHz and left-hand circularly polarized gain variation between 11 dBi to 13 dBi. The 3-dB beamwidth at 11 GHz is around 50°. The horn is used as the feeding source in a spatially fed array, particularly a reflectarray, to validate radiation characteristics in broadband operation.