RFID on the Road-Some Considerations About Passive Tag Antennas

This paper presents an investigation of tag antennaperformance in the scenario of a passive RFID tag placed on anasphalt road and inquired by readers in vehicles. Three typesof antennas were chosen and their properties were studied forvarious dielectric properties of the asphalt paving. Water onthe pavement (e.g. due to rainfall) was also taken into account,with various layer thicknesses. Based on the results of numericalexperiments performed using the finite-difference time-domain(FDTD) method we demonstrate how the communication rangebetween the tag and a reader varies depending on the materialssurrounding the tag and wave polarization