Three-dimensional SIW and high-performance air-filled SIW for millimeter-wave substrate integrated circuits and systems

Emerging millimeter-wave frequency applications require high performance, low-cost and compact devices and circuits. This is the reason why the Substrate Integrated Waveguide (SIW) technology, which combines some advantages of planar circuits and metallic waveguides, has focused a lot of attention in recent years. However, not all three-dimensional metallic waveguide devices and circuit are integrable in planar form. In its first section, this paper reviews recently proposed three-dimensional SIW devices that are taking advantages of the third-dimension to achieve either more compact or multidimensional circuits at millimeter wave frequencies. Also, in a second section, special interest is oriented to recent development of air-filled SIW based on low-cost multilayer printed circuit board (PCB) for high performance millimeter-wave substrate integrated circuits and systems.