Sub-Terahertz Monolithic Metal 3D-Printed Corrugated Horn Antenna with High Cross-Polar Discrimination

This letter presents a high-performance corrugated horn for the sub-terahertz, manufactured monolithically using high-precision 3D printing technology based on Micro Laser Sintering (MLS) of stainless-steel powder. The horn features 45° inclined corrugation stubs that allow the building of the component with its axis vertical without any internal support structures. This ensures circular symmetry of the horn and high cross-polarization discrimination, and circumvents radiation performance degradation, typical of tilted printing. Departing from traditional designs, the horn also incorporates a rectangular-to-circular waveguide adapter, not only enhancing compactness but also avoiding errors and losses associated with assembly. The stainless-steel antenna was plated with gold. The prototype, measuring 10.8 mm × 10.8 mm × 29.7 mm, exhibits outstanding performance with a peak gain from 18 to 22 dBi, and >36 dB cross-polar discrimination over the frequency band of 145-225GHz. This is the first demonstration of 3D-printed corrugation structures in corrugated horns showing high performance beyond 100 GHz.