E-band 3-D metal printed wideband planar horn array antenna

This paper presents a wideband and high efficiency corporate-fed horn array antenna in the E-band. A horn antenna is used as the unit cell of the array. The radiation pattern and grating lobe levels of the unit cell are improved by splitting the horn's aperture with a septum in the E-plane. A ridge gap waveguide corporate distribution network feeds the horns with the same amplitude and phase via coupling apertures. A prototype consisting of 4 × 4-element horn array antenna is manufactured by Direct Metal Laser Sintering (DMLS) 3D printing technique. The proposed antenna has a relative bandwidth of 24% with input reflection coefficient better than -10 dB and simulated total antenna efficiency better than 85% over the 69-88 GHz frequency band.