A Low-Cost Millimeter-Wave 5G V2X Multi-Beam Dual-Polarized Windshield Antenna

Design procedure and experimental validation for a millimeter-wave (MMW) vehicular antenna with simultaneous multi-beam, for 5G V2X application, is presented. The design overcomes the constraint for requiring both wide angular coverage and high gain through a compact multi-array design. Each array is designed to have a fixed beam direction and sufficient beamwidth so that the overall pattern guarantees simultaneous coverage in the elevation plane. The multi-array idea is a cost-effective technique compared to employing phase shifters and beam steering of a single array and avoids latency associated with beam steering. The proposed design is composed of three compact dual polarized patch arrays. Each array covers different elevation angles, and their beam maxima are chosen to be at 10°, −20° and −40° with respect to the normal of the windshield. The antenna covers the entire 28 GHz 5G band which ranges from 26.5 GHz to 29.5 GHz. Each feeding network is designed to minimize beam scanning with frequency. Dual-polarized antenna arrays are implemented to provide polarization diversity. Antenna mounting behind the laminated windshield have been investigated and proven to have a negligible effect on the antenna matching and a minor effect on the radiation pattern.