A Ku-Band Circular-Polarized Horn Antenna Based on a 3D Printed Polarizer

In this paper, a compact circular-polarized horn antenna is presented, based on a proposed 3D printed polarizer. The antenna consists of a transition between rectangular and circular waveguides, a septum polarizer for liner-to-circular polarization conversion, and a conical horn for radiation. By employing the 3D printing technique, the configuration printed with resin material will behave as the supporting structure, where the outer walls could be copper plated as boundaries; more importantly, the electric property of cured resin is also utilized to form a septum for phase delaying, finally realizing circular polarization (CP). At the feeding port of the designed horn, the simulation shows a superior reflection of -20 dB, covering the entire Ku band from 12 to 18 GHz. Accordingly, the axial ratio (AR) of CP is within 1.4 dB crossing the operational bandwidth, with realized gains between 9.8 and 12.9 dBi. The proposed work has the advantages of an integrated and compact configuration, light weight, and high fabrication accuracy but with low fabrication cost.