Arrangement for position-line or location determination of passive code or information carriers with respect to the identification device (identifying device)

摘要

Systems for the identification of passive code or information carriers have been known for a long time. Until now, precise position-line or location determination have been problematic, since it has normally been necessary to determine the field strength or modulation maximum for this purpose. If, however, at least two transmitting antennas are operated in antiphase, then a narrow compensation zone is produced between the antennas, in which compensation zone the code carrier can be identified considerably more accurately. If a code carrier comes into range of a such a transmitting device, said code carrier is supplied with energy and it starts a code transmission. If this code carrier now moves into the compensation zone, then the code transmission is suppressed. The absence or the recurrence of the code is used for position-line or location determination.