Additive manufacturing of substrate integrated waveguide components

This paper presents the recent advances in the implementation of substrate integrated waveguide (SIW) components and circuits by additive manufacturing (AM) techniques. The use of AM allows introducing novel features in the design of SIW structures, ranging from fully three-dimensional geometries (impossibly to obtain with standard planar circuits technologies), to the local modification of the dielectric permittivity and loss tangent of the 3D-printed material (which allows for novel classes of components and resonant cavities with modified quality factor). The implementation of a 3D-printed SIW resonant cavity is presented, with the aim to assess the technology and characterize the material. Subsequently, a 3D-printed SIW structure with four bends in the E-plane is presented and validated, as an example of a fully three-dimensional geometry. Finally, the use of 3D-printed material with different infill percentage is shown, with the aim to modify the quality factor of SIW resonant cavities and design filters with improved performance.