Patents Assigned to Cotag International Ltd.
  • Patent number: 4922261
    Abstract: In an inductive communication system (11) in which transmit (16) and receive (18) aerials are in communication with a transponder (40), one of the aerials, e.g. the receive aerial (18), is arranged in two parts (61,62), one of the parts (61) being closely mutually-inductively coupled to the transmit aerial, and the other part being remote from the transmit aerial, so that the interference signal received by the receive aerial from the transmit aerial is substantially cancelled by the mutually inductive coupling. The two parts (61,62) are preferably parts of a single continuous conductor. Alternatively one of the parts may form a tapped coil with the other aerials. The aerials may be coaxial and/or coplanar.
    Type: Grant
    Filed: November 27, 1987
    Date of Patent: May 1, 1990
    Assignee: Cotag International Ltd.
    Inventor: Kevin O'Farrell