A Wideband E-plane Vertical Transition from Rectangle Waveguide to Groove Gap Waveguide

Gap waveguide (GW) technology solves the electrical contact problem through a contactless way and makes the packaging of multilayer millimeter wave systems much easier. In this work, a wideband E-plane vertical transition from hollow rectangle waveguide (RW) to groove gap waveguide (GGW) for multilayer millimeter-wave packaged system is proposed. An inverted bended stepped structure is designed for wideband impedance matching between the vertical RW and the horizontal GGW. An air gap exists between the bended steps and the cover of GGW to maintain the advantage of contactless. To avoid resonation between the bended steps and the top cover plate, the width of the bended steps is narrowed and a rectangular region is cut off to reduce the surface of the bended steps further. A Ka-band prototype of the transition is designed, fabricated and tested, over the entire Ka-band, the measured insertion loss is less than 0.15dB, and the return loss is better than 20dB.