On the effect of mutual coupling on LF and UHF tags implemented in dual frequency RFID applications

The interaction between passive Low Frequency (LF) and Ultra-High Frequency (UHF) tags in a dual frequency Radio Frequency Identification (RFID) tag is studied. This interaction is observed by building a dual frequency system from commercially available readers and experimentally determining the read range with the mutual coupling effects between the antennas. It is shown that by proper placement of the tags the individual performance of each tag can be preserved in the presence of mutual coupling.