Bandwidth-Enhanced Grid Array Antenna for UWB Automotive Radar Sensors

This communication presents the design of grid array antenna (GAA) for automotive UWB radar sensors. The proposed GAA is constructed using astroid unit cells, which concurrently achieve high gain and bandwidth. The GAA consists of 33 radiating elements and are excited using a common transmission line center fed by a 50-Ω coaxial probe. Furthermore, amplitude-tapering techniques are employed to lower the sidelobe level (SLL). The prototype antenna is fabricated and experimental results are presented. The developed amplitude-tapered GAA provides 2.5 GHz effective operational bandwidth with VSWR ≤ 2 and gain variation less than 3 dB. The measured peak gain is 13.87 dB at 24 GHz.