A Wideband, High Gain and Low Sidelobe Array Antenna for Modern ETC Systems

Modern electronic toll collection (ETC) systems are currently moving towards a system design that is capable of fast and optimal payment handling for single lane. Thus, the antenna roadside reader unit (RSU) needs to provide sufficient coverage over vehicle lane during cycle. In this paper, left-hand circularly polarized (LHCP) 2×4 array proposed European standard RSU readers at 5.8 GHz. The consists patch element antennas with parasitic elements enhance gain bandwidth. Sequential phase rotation feeding networks applied make low-profile. By using optimized nut-shaped metasurface, can achieve higher due concentrated radiation power in boresight direction. has wide impedance bandwidth 2.34 GHz (37.73%), axis ratio 2.07 (32.9%), high 17 dBi, sidelobe level (SLL) lower than -15 dB Especially, half-power beamwidths 34∘ 17∘ horizontal vertical planes, respectively, which covers space while avoiding interference other lanes. performance verified by measured results. It showed promising candidate ETC applications.