Immobilizer circuit

摘要

An immobilizer device is configured for communicating with a base station. The immobilizer device includes an antenna circuit including three orthogonally-oriented antennas configured to receive a signal from a field generated by a base station. A power circuit is configured to draw power via the field on each of the antennas, and a communications circuit is configured to communicate with the base station via any of the antennas. The strength of the signals received via the antennas is evaluated and used to select one of the antennas for use in data communications and, if appropriate, as a power supply.

主权项

1. An immobilizer device for communicating with a base station, the immobilizer device comprising:
an RF antenna circuit including three antennas orthogonally-oriented relative to one another, each said antenna being configured to receive wireless transmissions from the base station, the RF antenna circuit having for each antenna an associated antenna channel carrying signals received by that said each antenna; a wireless power circuit connected to the RF antenna circuit and configured to generate power using signals received from the base station via at least one of the three antennas; a communications circuit connected to the antenna circuit and configured to
select one of the antenna channels exhibiting a signal strength that is higher than that of the other said antenna channels, andsupply signals from the selected antenna channel to the wireless power circuit, the wireless power circuit employing the supplied signals to generate power; and a logic circuit configured to process data communications on at least one of the antenna channels, and to generate a data communication for transmission to the base station using the communications circuit and at least one of the antennas; wherein the communications circuit and the logic circuit operate using the power generated by the wireless power circuit.