Design and Manufacturing of Ka-Band Horn Antennas Using 3D Printing: An Expanded Study with Enhanced Comparative Analysis

This paper presents an expanded study on the design, fabrication, and characterization of Ka-band (30 GHz) pyramidal horn antennas manufactured via high-resolution 3D-printing. Both polylactic acid (PLA) and stereolithography (SLA) processes were employed, followed by conductive spray metallization. Detailed background on antenna theory, including surface-roughness considerations based on the Rayleigh criterion, is provided to highlight potential effects on antenna performance. The 3D-printed horns demonstrate excellent agreement in gain and radiation patterns compared to a commercial standard-gain horn. These results validate that rapid and low-cost 3D printing can yield high-performance millimeter-wave horn antennas, making the approach attractive for prototyping and small-scale commercial applications.