Ultra-wideband grid array antenna for automotive radar sensors

This study presents the design of an ultra-wideband (UWB) grid array antenna (GAA) for automotive radar sensors. The GAA is constructed using long transmission lines and short radiating lines loaded with reactive circular disc elements to improve the bandwidth performance. The reactance loading provides more number of zeros in the antenna's reactance and hence provides a wider impedance bandwidth. A simplified equivalent circuit model is provided to understand the fundamental operation of the proposed GAA. The GAA is composed of 33 elements arranged in two rows to obtain narrow beam along one plane and relatively wider beam along the other plane. The proposed GAA is characterised by low profile, large bandwidth, high gain and fan beam radiation pattern. The prototype antenna is fabricated and experimental results are presented. From the experimental results, it is evident that the proposed GAA is suitable for UWB short range automotive radar systems to efficiently detect and prevent collision.