Low-Cost Gap Waveguide Technology Using Shallow Grooves and Glide-Symmetric Semicircular-Holes EBG Structures

In this letter, a novel electromagnetic bandgap (EBG) structure is proposed to manufacture gap waveguides (GWs) at high frequencies. The proposed EBG structure combines parallel shallow grooves and glide-symmetric semicircular holes, located on the upper and lower plate, respectively. Attributed to much-reduced milling depth, an efficient and easier manufacturing process can be realized for the proposed structure. Besides, the layout of the milling grooves can be flexibly adapted, making the proposed EBG structure more easily conformal with GWs. As a validation of the concept, both straight and bent side-by-side GWs exploring the proposed EBG structure are elaborately designed, fabricated, and experimentally tested, verifying the features of low loss and high isolation, respectively.