Highly Separated Automotive Radar Antennas

Automotive radar systems are improving road-user safety by their integration into collision avoidance systems. Often these radar systems need a high probability of detection using superior range and angular resolution. In this paper, the concept of highly separated radar antennas is introduced in the context of automotive radar systems. This novel technique can improve detection accuracy due to the processing gain improvement of the system, reduced antenna inter-element coupling and increased diversity gain by the combination of multiple-input multiple-output (MIMO) antennas at highly separated distances. The diverse spatial scattering reflected from the targets improves the overall response and in this paper results are compared for $\mathrm{a}0.5 \lambda$ and 45 cm separation for an frequency modulated continuous wave (FMCW) multiple input multiple output (MIMO) antenna system using substrate-integrated waveguide (SIW) receiver antennas.