2017 Volume 6 Issue 9 Pages 548-553
We propose a waveguide to microstrip line transition which perpendicularly connects one waveguide and two microstrip lines. Because the proposed transition consists of only a waveguide and a dielectric substrate, the configuration can be simplified. Additionally the transition does not need via holes on the substrate. This configuration reduces manufacturing complexity and cost. We assume to co-locate the transition and a patch array antenna on the dielectric substrate for millimeter wave automotive radar modules. Because the proposed transition suppress undesired radiation by multi-stage impedance transformers, the desired radiation pattern from the array is not worsen. The small radiation from the transition is shown by simulation. Additionally we fabricate 4 × 4 planar patch array antenna with the proposed transition. Measured and simulated radiation patterns are introduced.