Low cost wireless (resistive) sensor based on impedance coupling/modulation using MRC

摘要

A system for transmitting data signals from a sensor on a vehicle through magnetic resonance coupling (MRC). The system includes a control circuit having a base coil, a variable current source, a variable capacitor and a control load, where the variable current source and the capacitor are tuned to provide a predetermined AC current to the base coil so as to generate an oscillating magnetic field at a predetermined frequency. The system also includes a receiver circuit associated with the sensor, where the receiver circuit includes a receiver coil, a tuning capacitor and a variable resistive load. The receiver coil is tuned and magnetically coupled to the base coil at the predetermined frequency. A change in the variable resistive load in the receiver circuit in response to a sensor measurement causes a change in the voltage across the control load that gives an indication of the sensor measurement.

主权项

1. A magnetic resonance coupling (MRC) circuit comprising:
a control circuit including a base coil, a variable current source, a variable tuning capacitor and a control load, said variable current source selectively providing a predetermined current to the base coil so as to generate an oscillating magnetic field at a predetermined frequency; and at least one receiver circuit including a receiver coil, a tuning capacitor and a sensor that measures an environmental condition, said receiver coil being tuned to a resonant frequency that causes it to be magnetically coupled to the base coil at the predetermined frequency, wherein sensor measurements provided by the sensor in the at least one receiver circuit cause a change in the magnetic coupling between the base coil and the receiver coil that causes a change in the voltage across the control load.