Design and development of a multimode waveguide corrugated horn antenna using 3D printing technology and its comparison with aluminium-based prototype

Three-dimensional (3D) printing technology based antenna structures have many promising applications. In this study, a triple mode circular waveguide horn antenna with corrugated chokes is presented. In this antenna configuration, three individual modes consisting of TE11, TM01, and TE21 are generated in a single structure. The horn antenna prototypes used precision milling and 3D printing process for the aluminium and 3D printed horn antenna prototypes, respectively. The aluminium prototype is used as a reference antenna for comparing the 3D printed horn prototype. For the 3D printed antenna, Polycarbonate - Acrylonitrile Butadiene Styrene (PC-ABS) material is used and later coated with conductive silver ink. Simulation and aluminium based prototype antennas achieve a common bandwidth of 7.45-8.00 GHz for all the three modes. However for the 3D printed antenna prototype, the achieved bandwidth is from 7.40 to 7.89 GHz. The aluminium and 3D printed horn prototypes were also tested for radiation pattern quality. While aluminium-based prototype agrees closely with the simulation results, the 3D printed horn shows a reduced gain, higher cross-polarisation levels while keeping the pattern beamwidths similar to the simulated and aluminium-based horn prototypes.