A frequency steerable Substrate-Integrated Waveguide slot antenna for 77 GHz radar application

For a low cost radar system a serially fed, linear and equidistant waveguide slot antenna has been developed. A meander shaped waveguide path allows a frequency steerable main lobe without additional mechanical or electrical components. The antenna design focused on a maximum steering angle of ±60°. In order to further reduce the costs and simplify fabrication of the antenna a Substrate-Integrated Waveguide (SIW) structure was used. A new concept to reduce the parasitic coupling of these structures has been investigated. To fulfill the requirements on the radiation characteristics and matching of the antenna, a new slot shape and a cavity based waveguide-SIW transition were designed. Simulations and measurement results show that the antenna could be realized successfully.