In this paper, a broadband and simple vertical transition between substrate integrated waveguide and standard air-filled rectangular waveguide is design and experimentally verified. From full-wave simulation of the structure, a relative bandwidth of 19.5% in W-band with return loss better than 20dB is reached. Then, five copies of back-to-back connected transitions are fabricated on RT/Duroid 5880 substrate. The experimental results show that the transition pairs have an average of 15% relative bandwidth with return loss better than 12dB and insert loss lower than 1.2dB. To explain the differences between simulated and tested results, an error analysis is presented.
Low profile broadband substrate-integrated waveguide to rectangular waveguide transition for W-band automotive radar