Active E-Plate with Slot Antenna

Active e-plate is designed and tested for radio-frequency identification (RFID) of vehicles. The e-plate is designed by adhering active RFID module to a metal license plate with slots on it. The slots serve as RFID tag antenna, which are carefully designed without damaging the layout of characters and numbers on the license plate. In the prototype, e-plate antenna of slot width of 1 mm on metallic license plate is designed for RFID operating at 2.45 GHz. Both numerical simulation and test demonstrate that the slot antenna has desired impedance bandwidth, high gain and multi-beam radiation pattern as required for vehicle tracking. The measured read range of the proposed active e-plate is larger than 92 m.