Artificial lens for third-generation automotive radar antenna at millimetre-wave frequencies

A focusing system based on low-cost foam printed technology is investigated. The design is based on artificial lenses consisting of stacked parallel-plate waveguides of various lengths. The foam technology allows a single block configuration with the primary source. As the dimensions of the lens are at least 10λ₀, full-wave analysis is not appropriate for fast design. A theoretical model based on ray tracing, Goudet´s formula and using an array factor is proposed and validated by experiment. Simulations and experimental results show that the model is sufficiently accurate for fast design and optimisation. The low-cost technological solution proposed can potentially meet specifications for collision avoidance radar at millimetre-wave frequencies.