Leakage characteristics of substrate integrated waveguide with parallel metallic plates

The leakage characteristics of the substrate integrated waveguide are presented. The numerical method based on the hybrid generalized scattering matrix (GSM) is successfully validated by using the published measured data of the SIW designs in Ku- and Ka-bands. The new structural parameters of the SIW, including the thickness of the periodical metal wall, and the width of the extended parallel metallic plates are reported. The theoretical extractions show that the thickness of the metal wall seriously affects the cutoff frequency of the SIW. The additional metallic plate can induce additional leakage when the SIW is in the fast-wave region.