Additive manufacturing technologies are currently envisaged to boost the development of a next generation of microwave and millimeter-wave devices intended for, among others, satellite telecommunications, navigation, imaging, radio-astronomy, and cosmology. Due to their excellent electromagnetic and mechanical properties, all-metal waveguide components are key building blocks of several radio frequency (RF) systems used in these application domains. This article reports on the prospects originating from the application of all-metal 3D printing to the manufacturing of high-performance microwave waveguide devices. The technology investigated is the selective laser melting process, where a laser beam is used to fuse metal powder particles spread over a building platform. The complete parts are built by overlapping several constant-thickness layers. An overview on process parameters, material properties, and design rules is reported for this technology. The electromagnetic properties of test samples built in Al and Ti alloys have been experimentally characterized. A robust design of Ku/K-band filters aimed at satellite telecommunications has been implemented in several prototypes manufactured in Al. The corresponding measured performance confirm the applicability of the laser selective melting process to the intended applications.

Additive manufacturing (AM) is emerging as a key technology for the minimization and integration of microwave antenna systems. Among the several AM processes, selective laser melting (SLM) is rather convenient for waveguide components, since it allows for all-metal parts with a mechanical accuracy within 30-60 μm and an equivalent surface electrical resistivity in the range of 10-20 μΩcm. This paper reports on the assessment of the SLM applicability to the manufacturing of dual-polarization waveguide components operating in Ka-band, namely, a septum polarizer, a smooth-wall feed horn integrated with the septum polarizer, and an orthomode transducer (OMT). In order to achieve high electromagnetic performance in the Kaband, the architectures have been optimized for the manufacturing process, above all in terms of orientation on the building platform and minimization of supporting structures. As a consequence, the corresponding prototypes exhibit measured performances in significant agreement with the predicted values. As an example, the return loss of all the components has been measured to be as high as 25 dB, while the measured isolation between the rectangular waveguide ports of the OMT is better than 47 dB.

Additive manufacturing technologies have been increasingly applied to the development of radio frequency components in the past few years. Indeed, the free-form capability of these processes allows for the design of novel components, whose actual implementation through conventional machining is rather complex or even not possible. This paper describes a monolithic WR51 component integrating three radio frequency functionalities, namely, bending, twisting, and filtering. Three aluminum prototypes with different bending/twisting radii have been manufactured through the selective laser melting process. They exhibit a measured rejection higher than 60 dB in 17.5 and 21.2 GHz, and a measured return loss better than 20 dB in 12.5 and 15 GHz. Significant mass and envelope reductions (higher than 60% depending on the bending/twisting radius) with respect to the reference subsystem with distinct waveguide components are achieved. These results assess the effectiveness of 3-D metal printing in the miniaturization and integration of waveguide systems.

This study describes an experimental research activity on the manufacturing of passive waveguide components by means of two additive technologies, namely the selective‐laser melting and the stereo‐lithography processes. The former is a power‐bed fusion process, for which aluminium, titanium, and steel powders have been considered in this study. The latter is based on the photopolymerisation of a resin vat. This technology has been applied in conjunction with an acrylonitrile–butadiene–styrene‐like polymer and a subsequent electrolytic copper plating for the metallisation of the internal channels. Wideband filters operating in Ku/K band have been developed as benchmarks, for which detailed comparisons between simulations and measurements are reported.

3D-printing is leading to a major transformation in many industrial and application sectors, ranging from medical to aerospace. In the space sector, 3D-printing has firstly been adopted for the development of structural and thermal parts, such as brackets and heat pipes. In more recent years, thanks to improvements in precision and surface roughness, 3D-printing technologies have steadily been investigated also for the development of radio frequency components and advanced payloads. Indeed, the unique features of 3D-printing, including the free-form capability and the ease for customization, make these manufacturing technologies very appealing in the development of complex radio-frequency front-ends for space applications, including New Space constellations and next generation software-defined communication satellites. They also enable a drastic simplification of mechanical designs by reducing the number of interfaces and assembling screws of large radio-frequency front-ends, thus leading to significant mass savings and higher integration. This paper briefly reports on recent advances in 3D-printing that have been carried out according to the current trends in radio-frequency front-ends for satellite communications.

In this letter, the design and the three-dimensional (3-D) printing of high-performance feed horns operating within Ku- and V-bands are presented. A smooth-wall architecture has been preferred in order to ease the manufacturing and to enhance the 3-D printing quality. A suitable design procedure has been developed for the synthesis of dual-band smooth-wall feeds. Single-band and dual-band all-metal prototypes have been manufactured through the selective laser melting technology. A remarkable agreement between the predicted and measured performances has been achieved also for the higher frequency Q/V-band feed horn with measured return-loss higher than 33 dB, cross-polarization lower than −28 dB, and peak gain of 25 dBi.