Design of a long-range rectangular coil antenna for RFID access control system

The identification distance of the traditional High Frequency (13.56MHz) antenna used in the access control system is only around several centimeters, bringing about an inconvenience for the users and decreasing the efficiency of the access system. This paper describes the design and calculation of a long-range identification antenna, whose identification distance can reach 0.9 meter, using two paralleled antennas set in-phase. In this way, the passenger can go through the access control system, just bringing a card (tag) instead of swiping it, and the tag can be detected and identified by the reader precisely.