A wideband siw-to-waveguide transition at w-band

In this letter, a wideband W-band substrate integrated waveguide(SIW) to air-filled rectangular waveguide transition is presented. The proposed transition shows a bandwidth wider than 19% due to a slot-coupled patch structure applied. To demonstrate the design, a back-to-back transition is fabricated mainly by the low-cost printed circuit board (PCB) technology. The measured insertion loss of a single transition is less than 0.6 dB within the bandwidth. Therefore, the proposed transition is available for millimeter-wave applications because of its good performance and compact structure.