Investigation of Additive Manufacturing for Broadband Choked Horns at X/Ku Band

Additive manufacturing is becoming a popular alternative to traditional manufacturing techniques as it has reached a suitable maturity and accuracy for microwave applications. The main advantage is that the manufacturing can be performed directly from the three-dimensional CAD model, available from the numerical simulation of the antenna, without significant modifications. This is a highly desirable feature, in particular for time and cost critical applications such as prototyping and manufacturing of small quantities of antennas. In this letter, we investigate accuracy and repeatability of selective laser melting manufacturing of fully metallic broadband chocked horns at X/Ku band. A complete batch of 15 antennas has been manufactured and validated in terms of matching, radiation efficiency, and volumetric radiation patterns throughout their operating bandwidth. Manufacturing accuracy and repeatability have been evaluated using RF parameters as performance indicators, comparing measured data and high-accuracy simulations. These indicators are compared to state-of-the-art values commonly found for traditional manufacturing. The radiation patterns have been correlated to the numerical reference using equivalent noise level as a performance indicator. For input matching, manufacturing repeatability has been quantified by defining an interference level.