Evaluation of Additive Manufacturing Techniques Applied to Ku-Band Multilayer Corporate Waveguide Antennas

In this letter, additive manufacturing technologies have been evaluated for waveguide antenna array prototyping at Ku band. Direct metal laser sintering (DMLS) and stereolithog-raphy have been assessed in terms of manufacturing limitations, electrical performance, accuracy, cost and weight, compared with traditional manufacturing methods. This assessment is performed on a corporate-fed waveguide array antenna for end-user digital broadcast satellite communications at Ku band. The objective is to manufacture this intricate multilayer structure as a single block, in order to prevent contact and leakage issues in the interface between antenna layers. This monolithic implementation is unfeasible with conventional milling in aluminum, renowned in the literature for its reliability in waveguide antenna implementation. A prototype has been machined with such technique as a reference for experimental results. A single block fabrication has been possible by DMLS, presenting a similar performance to the reference prototype. Experimental results, including impedance matching, realized the gain and axial ratio have been performed on the antenna prototypes. A 14.7% effective bandwidth has been obtained for the DMLS antenna.