Abstract:
A system (10) for monitoring a condition of a tire (12) of a vehicle (14) includes a tire-based unit (20) and a vehicle-based unit (40). The tire-based unit monitors a condition of the tire (12), assembles data indicative of the monitored condition, and transmits at least one radio frequency signal (32) including a signal indicative of the data. The vehicle-based unit (40) receives the radio frequency signal (32) and determines an actual reception success rate of the radio frequency signal. The vehicle-based unit (40) compares the actual reception success rate of each radio frequency signal (32) to known reception success rates corresponding to known tire positions on the vehicle (14) and identifies one of the known reception success rates that is closest to equal the actual reception success rate. The vehicle-based unit (40) associates the radio frequency signal (32) with the known tire position corresponding to the one of the known reception success rates.
Abstract:
A transmitter for use with a receiver responsive to a function request signal transmitted by said transmitter for performing a requested function. The transmitter includes a controller for providing a function command and an LC oscillator for providing the request signal at a fixed frequency in response to the command from the controller. The oscillator includes a semi-conductor having first, second, and third electrodes and a tank circuit including first, second, and third impedances. A surface acoustic wave resonator is connected from the first electrode to ground. A feedback capacitor is connected from the second electrode to said first electrode for reducing spurious frequency signals.