3-D printed substrate integrated slab waveguide for single-mode bandwidth enhancement

This letter presents the implementation of a broadband substrate integrated waveguide (SIW) by an additive manufacturing technique. A 3-D printed material based on Ninjaflex filament has been realized by fused deposition modeling. By changing the infill percentage, printed materials with different dielectric properties have been fabricated and experimentally characterized. Two materials obtained from the same filament with different infill percentages have been used for the implementation of a substrate integrated slab waveguide (SISW), which allows increasing the single-mode bandwidth compared with that of a standard SIW. The experimental results for the fundamental and second modes of SIW and SISW show a 50% bandwidth enhancement.