In this paper the design and test of a frequency modulated continuous wave (FMCW) radar to be used as electronic travel aid for visually impaired subjects are presented. The sensor is based on the Infineon BGT24MTR11 integrated circuit, whose output frequency has been controlled by the Analog Devices AD4158 integrated circuit. A transmitting and a receiving serial array of patch antennas have been designed and realized. The designed sensor uncertainty has been experimentally investigated, finding a worst case value close to the theoretical resolution of 0.6 m calculated from the FMCW signal band
