Communications through tires by radiofrequency identification

The communication performance of Passive RFTD tags mounted inside tires for application to automotive logistics are investigated at the purpose to evaluate the achievable reading ranges. The maximum performance, reaching up to 8 meters for tags integrating low power ICs, are estimated by simulations of a benchmark dipole tag in different positions inside the tire. The realistic performance are retrieved by simulating and measuring COTS helical tags whose characteristics of flexibility and durability make them suitable to overcome the stresses of tire applications. Computer simulations and then laboratory experimentations in real conditions allowed evaluating the influence of metal and the position inside the tire. It was also demonstrated that, once the tag position inside tire is established, there is an optimal length of the antenna maximizing the realized gain and consequently the tag read range.