A novel feeding technique for folded substrate integrated waveguide

Abstract

In this paper a novel feeding technique is presented using transition between microstrip-line segment and folded substrate integrated waveguide (FSIW), which provides very low insertion loss over wide frequency band and can be used for signal feeding in FSIW based waveguides and components. Concept of simultaneous transformation in mode and impedance by tapering central metal septum and removing upper ground plane precisely above the tapering over the transition section is used to design the novel transitions. The presented design procedures are applied on transitions for FSIW transmission lines operating in different frequency bands from C to K band. The concept is explained in detail with an example for transitions designed for FSIW operating in Ku band. All the designed structures are simulated using HFSS software. The designed FSIW with the transitions operating in Ku band is fabricated and the measured results are compared with simulated results and are found in good agreement. Dimensions of transitions designed for FSIWs operating in other frequency bands are tabulated.