KEYLESS VEHICLE ACCESS AUTHORISATION SYSTEM

摘要

The invention relates to a keyless vehicle access authorisation system. A control apparatus in the vehicle engages in a question-and-answer dialogue with a portable transponder and checks and then clears or blocks authorisation to unlock or lock the vehicle doors. An antenna for transmitting and receiving the question-and-answer signal is located in at least the outside mirror on the driver's side and the question-and-answer dialogue is initiated through switches activated by the door handles. The communications range between the portable transponder and the control apparatus in the vehicle is considerably greater as a result of the fact that an additional antenna (13) is located on at least the driver's side (FS) in the area of a rear side window or the rear vehicle door. Said additional antenna (13) is also connected to the common control apparatus (10) and can be used for transmitting the question signal of the control apparatus and/or for receiving the answer signal of the portable transponder. When transmitting, the two antennae (12, 13) generate a two-dimensional electromagnetic field as a result of their arrangement.