A D-Band Waveguide-SIW Transition for 6G Applications

In this work, a design of a transition from a standard D-band waveguide to substrate integrated waveguide (SIW) technology is presented for 6G applications. The waveguide is connected to an SIW by carving a slot at the bottom metal of the printed circuit board (PCB). A pair of vias is added to shift the inband null to a higher frequency, whereas a parasitic patch is used to improve impedance matching. A prototype of a back-to-back SIW transition is fabricated and measured using D-band VNA extenders. The measurement shows a −10 dB impedance bandwidth of 26.5 GHz (135–161.5 GHz) and a 3 dB bandwidth of 28 GHz (133.8–161.8 GHz). The transition can be integrated with a D-band antenna for 6G applications.