The assessment of the antenna circuit of a RF wheel unit

The main goal of this paper is to assess the behavior of an antenna used inside a car TiS (Tire Information System) module and to find a way for future possible improvements. We will present some simulations of the loop antenna integrated inside the TIS module. We will take in consideration three different situations: the standalone simulation for that module, the situation when the module is mounted on the rim, and the other one, when the module is simulated assembled with the rim and the tire. The placement of the module on the rim as well as the influences produced by the tire itself, are analyzed based on the simulations and evaluations of the impedance and the radiation efficiency. Some usual dimensions are considered for the rim and the tire.