Low-Cost Gap Waveguide Technology Using EBG Composed of Parallel Grooves and Glide-Symmetric Semicircular-Holes

In this paper, we propose a novel EBG structure to fabricate low-cost gap waveguides (GWs). The proposed unit cell of EBG structure consists of a pair of parallel shallow grooves with the glide-symmetric semicircular holes distributed laterally along the grooves, all positioned on the upper and lower metal layers. The much-reduced milling depth of the proposed EBG structure contributes to the advantage of efficient and low-cost manufacturing process. Besides, the proposed EBG can be more easily conformal with GWs within a compact feeding network because of the flexibly adaptable grooves and holes. As a proof of concept, both straight and side-by-side GWs are designed and measured to investigate the low-loss and high-isolation features of GWs exploiting the proposed EBG.