Empty SIW Technologies: A Major Step Toward Realizing Low-Cost and Low-Loss Microwave Circuits

Abstract

[EN] Substrate-integrated circuits (SICs) [1] have attracted much attention in the last several years because of their great potential. The first implementation of the concept can be found in [2] as a feeding mechanism for a slot array antenna. Deslandes and Wu [3], [4] used the term substrate-integrated waveguide (SIW) to define this waveguide integrated in a substrate where the lateral walls are synthesized with metallized via holes, and the upper and lower walls are the top and bottom metallization of the substrate.

Many other SICs have been developed since the appearance of the SIW. In the substrate-integrated slab waveguide [5], the guide is synthesized on a substrate by cutting an air hole in the center of an SIW, and the frequency operating bandwidth is increased. The ridge SIW [6] also increases the operation bandwidth by drilling cylindrical air holes in the middle of the SIW. The substrate-integrated nonradiative dielectric waveguide [7] uses a specific pattern of air holes as lateral walls, creating a dielectric waveguide channel that reduces the radiation losses with respect to the SIW. The half-mode SIW [8] reduces the size of the SIW by half by exploiting the fact that there is a symmetry plane along the propagation direction that is equivalent to a magnetic wall.