E-plane metallic RWG-to-SIW transition for large-scale MM-wave phased array antenna applications

A novel air-filled E-plane rectangular waveguide (RWG) to substrate integrated waveguide (SIW) transition, which is suitable for Ka-band large-scale antenna arrays, is presented. The power is coupled between the RWG and SIW through two slots: one etched on the SIW ground plane and the other cut through metallic RWG narrow side wall (E-plane). A back-to-back transition is designed, fabricated, assembled, and tested. Measured results show a good agreement with the simulated ones. An SIW attenuation loss ≤0.33 dB/1 cm and a transition return loss better than 10 dB have been experimentally obtained over the band 28.30–30.8 GHz.