Design and Implementation of an X-Band Horn Antenna With a Metamaterial Lens Using 3D Printing Technology

This paper presents the design and implementation of an X-band horn antenna, which operates over a frequency range of 7 - 9 GHz for small satellite communication systems in Low Earth Orbit (LEO), employing metamaterials and 3D printing technology. It was fabricated using a polymer-based material through a 3D printer and subsequently coated with copper. The horn antenna with a metamaterial lens (meta lens) and septum polarizer is fabricated as a single structure, eliminating the need for additional mechanical structures and parts for assembly of the antenna. This results in a significant reduction in weight compared to a conventional antenna manufactured using traditional methods. To enhance the directivity of the conical horn antenna, the meta lens horn antenna incorporates a periodic lattice-shaped metamaterial. Additionally, a septum polarizer is integrated to achieve circular polarization. The metamaterial lens used in this paper exhibits Near-Zero Refractive Index (NZRI) characteristics within the operating frequency band. It is positioned inside the conical horn antenna to compensate for the field phase difference between the horn's edge and vertex. This compensation leads to a uniform phase distribution across the aperture, resulting in improved antenna directivity. The simulated and measured results show that the meta lens enhances the gain by over 1 dB within the frequency band of interest compared to the conventional horn of the same size. Furthermore, it exhibits a return loss below 20 dB. The proposed antenna was fabricated as a monolithic lightweight structure using the Fused Deposition Modeling (FDM) technique and subsequently metalized through the electro-less plating process. The stability of electrical properties has been verified in a thermal vacuum environment test to ensure its functionality in an LEO environment, characterized by significant temperature fluctuation.