Vivaldi antenna for railway cutting monitoring

A planar Vivaldi antenna was reconstructed and assessed as a candidate for a short range, high range resolution railway cutting monitoring radar. The initial flare section of the Vivaldi antenna was found to control the return loss of this type of antenna at lower frequencies, and a compact antenna for 120% fractional bandwidth was demonstrated experimentally. Group delay was used as a UWB antenna assessment method, and the prototype antenna gave reasonable performance across the lower half of the band considered.