Magnetic field intensity in near field zone of loop antenna for RFID systems

The structure of a loop antenna of electrically large diameter with the loop perimeter split by capacitors in the form of planar two-wire (PTW) lines is considered. The antenna characteristics are calculated for one- and two-sided arrangement of the PTW lines and the obtained data are compared to the results of measurements. It is shown that the arrangement of PTW lines significantly influences the distribution of current over the loop perimeter.