Design and Fabrication of a Dielectricless Substrate-Integrated Waveguide

A process for the fabrication of dielectricless rectangular waveguides (RWGs) integrated in the substrate is presented and experimentally validated. First, two complementary circuits are realized through milling the guide in a substrate and, then, are metallized with traditional additive processes used in printed-circuit board industry. Next, the circuits are joined together, and electric continuity is enforced through two additional rows of conductive holes along the guide sidewall, as it occurs in the substrate-integrated waveguide technology. A comparison between the propagative characteristics of a classic RWG and a waveguide with this methodology is reported. Finally, a slotted waveguide realized by this technology is fabricated and measured.