Reduction of dielectric losses in substrate integrated waveguide

The impact of different loss mechanisms on the attenuation of the substrate integrated waveguide (SIW) is investigated. Using a multilayer PCB technology, an air-cut region is introduced in the SIW structure to reduce the attenuation caused by dielectric losses. Numerical results obtained using a mode-matching technique verify that the attenuation constant of the SIW can be reduced significantly if the width of the air-cut is chosen properly.