Wideband Waveguide to SIW to Microstrip Transition for 79 GHz Automotive Radar Antenna Characterization

This paper presents a novel low-cost transition technology for interconnecting micro-strip line to SIW to WR10 waveguide on a thin substrate designed for characterization of 79 GHz antennas. The proposed transition is based on matching the WR10 waveguide to an SIW cavity using a dielectric cube of a material with lower dielectric constant followed by an SIW-to-micro-strip-line transition. This paper shows that utilizing the dielectric cube can increase the bandwidth of the transition on thin substrates. The proposed transition has an insertion loss of less than 1dB over a wide range of frequencies (76GHz to 81GHz). Measurement results are in good agreement with the simulations.