3-D Printed Wideband Millimeter-Wave Horn Antenna With Conical Radiation Pattern

A wideband millimeter-wave (mmW) circular aperture horn antenna with a conical radiation pattern realized by the metallic three-dimensional (3-D) printing technology is presented in this letter. The proposed structure consists of a coaxial waveguide and a quadruple-ridged conical horn. The horn antenna is fabricated using a direct metal laser sintering (DMLS) technology, and both manual polishing and yellow-gold coating are employed to realize a surface roughness of Ra = 1.6161 μm. The overall size of the fabricated antenna is 20 mm × 20 mm × 15.8 mm. Experimental measurements show that a wide relative impedance bandwidth of 60.7% and a peak gain of 11.4 dBi can be achieved within the frequency band of 24.9-46.6 GHz.