A novel ku-band circularly-polarized horn antenna based on a ridged wall

In this paper, a novel wideband (31.5 % bandwidth) circularly-polarized antenna based on a ridged wall is presented. A pair of ridges on the inner wall of the horn serves as an inbuilt polarizer, which can generate left-hand or right-hand circular polarization without any additional polarizer. The ridged wall is placed at 45° with respect to the input port linearly polarized wave to generate a 90° phase delay and obtain the desired circular polarization at the aperture. The simulated results show that the antenna works great in the whole Ku satellite band (from 10.7 to 14.7 GHz) with more than 20 dB return loss and below 1 dB axial ratio. The antenna can be fabricated using traditional computer numerical control machining techniques or the new 3D metal additive manufacturing processes.