Evaluation of the impact of 3D-printed surface roughness on the radiation efficiency of a coaxial horn antenna operating at the ka-band

Abstract

This work presents a systematic analysis of the impact of surface roughness on the radiation efficiency of a 3D-printed coaxial horn antenna, aiming to contribute to the investigation of the effects of 3D-printed surfaces on antenna performance, an area for which a methodical evaluation remains largely absent in the current literature. Simulations with a finite conductivity boundary in Ansys HFSS were conducted to evaluate surface roughness through the perspective of the Groiss and the Huray models, considering various conductivity values. Radiation efficiency was verified for each model. The results obtained with the Groiss model confirmed that surface roughness degrades radiation efficiency, with this impact being more pronounced at lower conductivity values. The Huray model treats surface roughness as a distribution of spheres resembling the textures commonly observed in 3D-printed surfaces. This model illustrated how larger particle radii and increased particle density consistently lead to reduced efficiency, though this effect is also less prominent at higher conductivity levels.