It is known in the art to provide remote activation devices, especially in connection with vehicles. These often take the form of a small electronic fob that can be conveniently carried by the vehicle operator. The fob usually contains a radio transceiver that communicates with a transceiver and control system of the vehicle. For example, when a user activates an “unlock” button on the fob, the fob sends a radio message to the vehicle control system, which then causes one or more of the door locks to open.
One recent modernization of ignition systems is the advent of “keyless” ignition systems with “push-button” (or other keyless) engine starting. Such systems use an electronic “key” (code within the fob) that does not have to be inserted into an ignition switch of a vehicle, but merely be present in a predetermined authorization zone, such as the passenger compartment of the vehicle. When the control system detects that an authorized electronic key is within the authorization zone, the driver may start the vehicle by simply activating (e.g., pressing) the ignition starter (e.g., button). If the control system does not detect an authorized key within the authorization zone, the control system disables the ignition system of the vehicle so that the vehicle cannot be started.
One drawback of keyless ignition systems is that they operate at relatively low power levels so as not to extend the authentication zone beyond the passenger compartment of the vehicle. Also, typical keyless ignition systems operate within a relatively low frequency band (e.g., 20-134 kHz). Both these conditions render conventional keyless ignition systems susceptible to magnetic or electrical interference, which may impede or prevent authentication. Failure or delay in properly authenticating a valid vehicle user may frustrate the vehicle user and detract from her/his enjoyment of the vehicle.
Accordingly, it is desirable to provide a keyless ignition system for a vehicle. Also, it is desirable to reduce interference within the vehicle during keyless ignition authentication. Additionally, other desirable features and characteristics of the present invention will become apparent from the subsequent description taken in conjunction with the accompanying drawings and the foregoing technical field and background.