Study of Bend Discontinuities in Substrate Integrated Gap Waveguide

This letter presents a study of bend discontinuities in the substrate integrated gap waveguide (SIGW), and proposes a simple solution to minimize the discontinuity effects. Both curved and chamfered right-angle bends are studied. It is found that with a proper ratio of the chamfered length and the bend via diameter, the possible cavity resonances can be suppressed and the desired performance is achieved. The curved bend, however, allows the bend via to have a larger diameter, which could be required due to the fabrication issue. This letter will be of great help to realize future feeding networks for SIGW antenna arrays or other types of cost-effective SIGW passive components, where many discontinuities are naturally present. The proposed discontinuity solution is validated experimentally by a fabricated SIGW prototype of two 90° bends.