In this paper a novel antenna for an electromagnetic assistance system for autonomous walking of blind or visually impaired people is presented. Its main aim is to detect obstacles that the white cane is not able to intercept, in particular those that can hurt the head or thorax zone. The proposed antenna has a fan beam radiation pattern, works at 24 GHz, in a frequency band reserved for ISM (Industrial, Scientific and Medical) applications. The antenna is designed using a numerical electromagnetic tool and its capability to detect a wide set of obstacles was investigated through numerical simulations and experimental measurements. Results confirm the good performances of the antenna and its capability to extend by a few meters the region usually explored by the white cane.