A new transition for SIW and microstrip line

Transition is a critical component to integrate the substrate integrated waveguide and planar circuits. In this paper, a novel transition design method is presented. The new approach combines slots and multi-section stepped impedance transformers directly within a single section of microstrip line. Two new transitions working in U band and Ku band have been studied. The results show that these two transitions all have good performance and achieve good impedance matching in their operating frequency bands. The sizes of the new structures are more compact than the traditional tapered ones.