A Review of Compact Substrate Integrated Waveguide (SIW) Interconnects and Components

This paper presents a review of the most common strategies to miniaturize substrate integrated waveguide (SIW) structures, and their application to the implementation of microwave components and antennas. The folded SIW, half-mode SIW, ridge SIW and substrate integrated slab waveguide (SISW) are presented and discussed. Most of these structures allow to reduce the footprint of regular SIW interconnects, and in some cases they exhibit broader single-mode bandwidth. These structures have been adopted for the implementation of microwave components and antennas with smaller size and comparable performance, including compact cavity filters and cavity-backed antennas: the design and realization of these components is described through examples and applications.