Design and simulation of the tire pressure sensor based on the SAW resonator and the tire capacitor impedance

A novel tire pressure sensor based on the SAW resonator and the tire capacitor impedance was researched, and the sensor can measure the tire pressure wirelessly and passively according to the relation between the tire pressure and the tire capacitor impedance and the relation between the tire capacitor impedance and the resonant frequency of the sensor circuit. The novel sensor structure was introduced, and four L type, five T type and five pi type sensor circuit structures were analyzed and their frequency characteristics were simulated. The simulation results show that the T1 ~ T5, pi1, pi2, pi4 and pi5 type sensor circuit structures are suitable for the tire pressure sensor, and the performance of the T3 type sensor circuit structure is the best among them. The sensitivities of the sensor were calculated and the best sensor circuit was designed according to the simulation and analysis results.