A long read range RFID tag design for metallic objects

The technology of Radio Frequency Identification (RFID) has been used to speed up the tracking process as well as to increase the efficiency of the product management process in various industries. In developing RFID solution, the core of all the questions is how to design high performance and suitable RFID tags for practical applications. However, since RFID tags are directly attached to objects, the antenna parameters, such as the input impedance, radiation pattern and the operating frequency, can all change depending upon the placement of the tag. In particular, when an RFID tag is placed near an object with high conductivity, its performance can degrade significantly [1]. Over the past few years, a vast amount of papers have been published on the topic of mountable RFID metal tags that adopt IFA (Inverted-F Antenna), PIFA (Planar Inverted-F Antenna), patch-type or nonplanar-loop antenna structures to overcome the problem of interference by metallic objects [2]–[5].