Broadband Transition of Substrate-Integrated Waveguide-to-Air-Filled Rectangular Waveguide

A single-layer right-angle broadband transition between the substrate-integrated waveguide and air-filled standard rectangular waveguide is proposed and demonstrated at the V-band. An aperture coupled patch with two pairs of inductive posts is employed to form the transition. An impedance bandwidth wider than 48% for return loss less than -10 dB is achieved. The proposed back-to-back transition is fabricated on a single layer substrate using the printed circuit board technology. The measured results of back-to-back prototype show that the insertion loss of a single transition is less than 0.5 dB. The measured results show a good agreement with HFSS simulation results. This transition with compact size, wide bandwidth, and low cost can be used for a variety of millimeter-wave circuits and systems.