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Fabrication of a High-Efficiency Waveguide Antenna Array via Direct Metal Laser Sintering

The direct metal laser sintering (DMLS) technique, using aluminum alloy, is adopted to fabricate a relatively large 8 ×8 wideband multilayer waveguide array with an integrated corporate-fed network in the Ku-band. This DMLS technique offers the flexibility to fabricate waveguide structures with complicated embedded structures with good reliability and high precision. It is favorably compared to the time-consuming machining technique when the array must be built in separate pieces and secured together. Experimental results show there is 1.0 ~ 1.5 dB gain improvement compared to one that is fabricated by machining technique. Antenna aperture efficiency is higher than 80% over a wide operational bandwidth and even exceeding 90% at most frequencies. This work shows that the metal-direct-printing technique is a promising manufacturing method for the fabrication of complicated waveguide antenna arrays.